See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/261908863 Megalastrum (Dryopteridaceae) of the Circumaustral Region: Chile, Argentina, and Southern Islands of the Atlantic, Pacific, and Indian Oceans ARTICLE in SYSTEMATIC BOTANY · SEPTEMBER 2010 Impact Factor: 1.23 · DOI: 10.2307/40802541 CITATIONS READS 8 70 3 AUTHORS, INCLUDING: Michael Sundue Germinal Rouhan 60 PUBLICATIONS 374 CITATIONS 43 PUBLICATIONS 334 CITATIONS University of Vermont SEE PROFILE Muséum National d'Histoire Naturelle SEE PROFILE Available from: Germinal Rouhan Retrieved on: 14 January 2016 Systematic Botany (2010), 35(3): pp. 461–475 © Copyright 2010 by the American Society of Plant Taxonomists Megalastrum (Dryopteridaceae) of the Circumaustral region: Chile, Argentina, and Southern Islands of the Atlantic, Pacific, and Indian Oceans Michael Sundue,1,3 Germinal Rouhan,2 and Robbin Moran1 1 The New York Botanical Garden, Bronx, New York 10456-5126, U. S. A. Muséum national d’Histoire naturelle, UMR CNRS 7205 ‘Origine, Structure et Evolution de la Biodiversité’, Botanique, 16 rue Buffon CP39, F-75005 Paris, France 3 Author for Correspondence (msundue@nybg.org) 2 Communicating Editor: Kenneth M. Cameron Abstract—In this treatment we revise the circumaustral fern species of Megalastrum found primarily between 33–45° latitude South. These species are found in the Valdivian temperate rain forests of Chile and Argentina, the Juan Fernández Islands in the South Pacific, the Tristan da Cunha archipelago in the southern Atlantic, and Île Amsterdam and Île Saint-Paul in the southern Indian Ocean. Megalastrum is absent from Australia and New Zealand. Seven species are treated in total. Two species and two varieties of Megalastrum have generally been recognized in Chile and the Juan Fernández Islands. In this treatment, we recognize four species for the region, one of which is elevated to the species rank (M. glabrius stat. nov.), and one which is new (M. masafuerae sp. nov.). Within the Tristan da Cunha archipelago, two species occur: M. aquilinum comb. nov., and another here described as new, M. peregrinum sp. nov. Île Amsterdam and Île Saint-Paul harbor one species that is described here as new: M. taafense sp. nov. For each species we provide a key, descriptions, complete synonymy, discussions, specimens examined, and illustrations. Keywords—Fern, Juan Fernández archipelago, Oceanic islands, pteridophyte, TAAF, Taxonomy, Trade winds, Tristan da Cunha archipelago. This paper treats the circumaustral species of Megalastrum Holttum occurring between 33°–45° south latitude. These species are found in the Valdivian temperate rain forests of Chile and Argentina, the Juan Fernández Islands in the south Pacific, the Tristan da Cunha archipelago in the south Atlantic, and Île Amsterdam and Île Saint-Paul in the south Indian Ocean. Megalastrum is absent from Australia and New Zealand. This study is one in a series of papers treating the genus in large geographic regions. So far we have published a treatment of the 18 species of Megalastrum in Brazil, Paraguay, and Uruguay (Moran et al. 2009a) and the nine species in the West Indies (Moran et al. 2009b). Other papers in this series will treat separately the remaining species; that is, those in Africa-Madagascar-La Réunion, Central America, and the Andean region of South America. Between any two of these regions there is little or no overlap of species. For a review of the taxonomic history and geography of Megalastrum, see Smith and Moran (1987) and Moran et al. (2009a). Christensen (1913, 1920) was the first to point out the distinctiveness of the group. He noted its characteristic lamina cutting and venation; namely, as one goes distally along the pinna, the basal basiscopic pinnules gradually become decurrent and broadly adnate to the pinna rachis. Correspondingly, the vein that supplies the broadly adnate segment or lobe arises from the pinna rachis, not the costule. Among ferns, this combined cutting and venation pattern is unique. Christensen (1913, 1920) pointed out another helpful characteristic: the form of the hairs on the adaxial surfaces of pinna rachises. Generally, these are coarse, whitish, septate, sharp-tipped, and antrorsely strigose or spreading (Smith and Moran 1987). Another distinctive character of Megalastrum is that the veins in almost all species end before the lamina margins in enlarged tips (hydathodes). This type of vein termination is uncommon among dryopteroid ferns, which typically have slender vein tips that reach the margin. Some other Dryopteridaceae may have conspicuous hydathodes, however, including Stigmatopteris C. Chr. (Moran 1991), the species of the monophyletic subsection Setosa of Elaphoglossum Schott ex J. Sm. (Mickel and Atehortúa 1980; Rouhan et al. 2004) and some species of Polystichum Roth such as P. punctiferum C. Chr. (Christensen, 1931). The above characteristics were first pointed out by Christensen (1913, 1920), who treated the species now called Megalastrum as the “group of Dryopteris subincisa” of subgen. Ctenitis. He assigned about 30 species to the group, of which two species, each with a second variety, occurred in Chile and the Juan Fernández Islands. These four taxa have been accepted in recent floristic accounts within the region (Marticorena and Rodríguez 1995). Since Christensen’s monograph, no further comprehensive study has been published for the species of Megalastrum occurring in Chile and the Juan Fernández Islands despite many subsequent collections. We also examined material from the oceanic islands of Tristan da Cunha, Île Amsterdam, and Île Saint-Paul from where Christensen later reported (1940) a third species that he believed was closely related to the Chilean species. The purpose of our study was to review the species of Megalastrum throughout the circumaustral region, examine relevant type specimens, and provide an up-to-date taxonomic treatment. Methods Herbarium specimens were borrowed from 25 herbaria, 17 of which had specimens from the region (see Acknowledgments). These specimens represent 108 separate gatherings. To show the variation in lamina cutting, silhouettes were prepared from herbarium specimens for all species. To do this, digital images were taken of basal pinna, and the images were then adjusted to provide a white background and a black lamina. Geographic coordinates were estimated for most of the specimens because this information was often not provided on the labels. Our estimates of geographic coordinates are given in brackets for the herbarium specimens cited below. Results We recognize seven species, of which three are new (M. masafuerae, M. peregrinum, and M. taafense). No infraspecific taxa are recognized. These species are keyed to, described, and illustrated below. A synopsis of their distributions is given in Appendix 1. A list of collectors and their numbers is given in Appendix 2. 461 462 SYSTEMATIC BOTANY Six of the seven species recognized are endemic to oceanic islands of recent volcanic origin. They are all under the influence of the prevailing westerly trade winds. The seventh species is found on mainland South America in the Valdivian forests of Chile and Argentina, which are temperate rainforests. Strangely, no species of Megalastrum are known from New Zealand, despite it being in line with the westerly trade winds. Megalastrum Holttum, Gard. Bull. Straits Settlem., ser. 3, 39: 161. 1986.—TYPE: Megalastrum villosum (L.) Holttum [basionym: Polypodium villosum L.]. Dryopteris subgenus Ctenitis C. Chr., group of D. subincisa C. Chr., Kongel. Danske Vidensk. Selsk. Skr., Naturvidensk. Math. Afd. ser. 8, 6: 32, 59. (1919) 1920. Dryopteris subgenus Ctenitis C. Chr. sect. Subincisae C. Chr., Index Filic., suppl. 3: 7. 1934. Ctenitis subgen Ctenitis C. Chr. sect. Subincisae (C. Chr.) Tindale, Contr. New South Wales Natl. Herb. 3(5): 252. 1965.—TYPE: Megalastrum subincisum (Willd.) [Volume 35 A. R. Sm. & R. C. Moran [basionym: Polypodium subincisum Willd.] Plants terrestrial; rhizomes erect to decumbent; petioles scaly toward the base, with 4–10 vascular bundles, the two adaxial bundles enlarged; laminae 1-pinnate-pinnatifid to 4-pinnate-pinnatifid, catadromic above the basal pinnae; basal pinnae inequilateral and more developed on the basiscopic side or (less commonly) equilateral; rachises, costae, and costules not grooved or only shallowly so adaxially, scaly and pubescent abaxially, densely pubescent on the adaxial surfaces, the hairs whitish, spreading to antrorsely strigose, multicellular, if glands present, these ca. 0.1 mm wide, spherical, shiny, yellowish to orangish, sessile to stalked; basal basiscopic segment of more distal pinnules becoming decurrent and adnate to the pinna rachises, the vein supplying the segment springing from the pinna rachis instead of the costule; hydathodes (enlarged vein ends) present adaxially; indusia absent or (less commonly) present, circular, brown, firm, in some species minute and fugacious; x = 41. Key to the Species of MEGALASTRUM in the Circumaustral Region 1. Hairs of the lamina margins 0.5–0.7 mm long, 4–7-celled, straight; indusia fugacious (sometimes absent), usually visible as a tuft of (1)5–10 erect acicular hairs, 0.5 mm long, emerging from the center of the sorus; rhizomes forming an erect trunk up to 1 m tall (Isla Masatierra, Juan Fernández Islands) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. inaequalifolium 1. Hairs of the lamina margins 0.2–0.4 mm long, 3- or 4-celled, curved, or the lamina margins glabrous; indusia present or absent, provided with indument 0.1 mm long including either cilia, sessile glands, and or 1–2 setae; rhizomes not forming an erect trunk . . . . . . . . . . . . 2 2. Indusia present, 0.3–0.8 mm wide; abaxial lamina surfaces between veins glabrous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Lamina margins glabrous; laminae abaxially lacking hairs; hairs of the adaxial pinna rachises 0.1–0.3 mm long (Juan Fernández Islands, Isla Masafuera) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. glabrius 3. Lamina margins sparsely ciliate, the hairs restricted to proximal portions of the ultimate segments; laminae abaxially sparsely pubescent along veins; hairs of the adaxial pinna rachises 0.4–0.8 mm long (Juan Fernández Islands, Isla Masafuera) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. masafuerae 2. Indusia fugacious or absent, 0.1–0.4 mm wide; abaxial lamina surfaces between veins glabrous to puberulent and /or glandular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Adaxial lamina surfaces between the veins sparsely to densely pubescent and glandular, the hairs 0.3–0.5 mm long, the glands evenly distributed (Gough Island) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. peregrinum 4. Adaxial lamina surfaces between the veins glabrous to sparsely pubescent, sparsely glandular or nonglandular, the hairs ca. 0.3 mm long, the glands near the costae only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Lamina margins flat, ciliate; indusia absent; adaxial laminae with hairs present on the veins and often between the veins, lacking glands (Chile, Argentina) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. spectabile 5. Lamina margins recurved, sparsely ciliate to glabrous; indusia present, fugacious (rarely absent); adaxial laminae lacking hairs, with or without glands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 6. Lamina surfaces between veins pubescent and glandular abaxially; hairs of the abaxial pinna costules 0.5–0.7 mm long, 5- or 6-celled; adaxial lamina surface nonglandular or with glands restricted to the costae (Tristan da Cunha and Gough Islands) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. aquilinum 6. Lamina surfaces between veins glabrous abaxially; hairs of the abaxial pinna costules 0.2–0.5 mm long; adaxial lamina surface nonglandular (Amsterdam and St-Paul Islands) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. taafense Taxonomic Treatment Megalastrum aquilinum (Thouars) Sundue, Rouhan, & R. C. Moran, comb. nov. Polypodium aquilinum Thouars, Esquisse Fl. Tristan d’Acugna 32. 1808. Phegopteris aquilina Mett. ex Kuhn, Fil. Afr. 121. 1868. Nephrodium aquilinum (Thouars) Hemsley, Rep. Voy. Chall., Bot., 1(2) 167, t. 39. 1885. Dryopteris aquilina (Thouars) C. Chr., Index Filic. 252. 1905. Ctenitis aquilina (Thouars) Pic. Serm., Webbia 28: 468. 1973.—TYPE: TRISTAN DA CUNHA. without date, du Petit-Thouars, L.-M. A. s. n. (lectotype here designated: P- P00713304!; duplicate P- P00713305!). Plants terrestrial; rhizomes not seen; fronds 0.5–1.0 m long; basal petiole scales ca. 4.0 × 0.2 cm, linear-lanceolate, light brown, translucent, minutely denticulate, twisted, the cells elongate; laminae 25–50 cm long, 3-pinnate-pinnatifid at base, 2-pinnate-pinnatifid medially; basal pinna 18 cm long, inae- quilateral, short-stalked to sessile; pinnules sessile, the basal segments frequently overlapping the pinna rachis, the largest pinnule of the basal pinna 6 cm long; pinna rachises abaxially glandular, scaly, and densely pubescent, the glands sessile, yellow, hyaline, 0.1 mm wide, the hairs 0.2–0.7 mm long, 3- or 4-celled, hyaline, acicular, the cross walls reddish, the scales 1.5–2.0 × 0.5 mm, ovate to lanceolate, light brown, translucent, entire, the cells isodiametric, adaxially glandular, scaly, and densely pubescent, the glands and scales similar to those of the abaxial side, the hairs 0.2–0.3 mm long, 2- or 3-celled, reddish, blunt-tipped; costules abaxially densely glandular, scaly, and pubescent, the glands like those of the pinna rachises, the scales 1.0–1.5 × 0.3–0.5 mm, otherwise similar to those of the pinna rachises, the hairs 0.5–0.7 mm long, 5- or 6-celled, otherwise similar to those of the abaxial pinna rachises, adaxially the costae densely glandular and pubescent, the hairs 0.5 mm long, 4-celled; laminar tissue between the veins abaxially 2010] SUNDUE ET AL.: MEGALASTRUM IN CIRCUMAUSTRAL REGION slightly pale, glandular, glabrous or with scattered erect hairs 0.2 mm long, adaxially darker in color, glabrous; veins not visible on either side of the lamina, abaxially glandular, pubescent, and provided with scattered 0.2 mm long uniseriate scales, the hairs 0.4–0.6 mm long, 4-celled, adaxially with glands along the segment costa, otherwise glabrous; lamina margins recurved, glabrous or very sparsely ciliate, the hairs 0.2–0.3 mm long, 2- or 3-celled, acicular, restricted to the proximal portions of the ultimate lobes; indusia present or rarely absent, fugacious, 0.1–0.4 mm wide, provided with ca. 0.1 mm long sessile glands, and sometimes with 1–4 ca. 0.1 mm long setae; n = 41 (Manton and Vida 1968). Figures 1M–R, 2, 3A. Etymology—From the Latin aquilinum, like that of an eagle. Du Petit-Thouars chose this specific epithet because he found the “root” (likely the rhizome) similar to the one of “Pteris aquilina” (= Pteridium aquilinum). This is a strange finding because the “roots” are probably not similar at all. Although we have not seen the rhizome of M. aquilinum, it is probably erect, like all other species in the genus, not creeping as in Pteridium. Distribution and Ecology—Endemic to Tristan da Cunha, Nightingale, Inaccessible, and Gough Islands in the south Atlantic Ocean, where it reportedly grows in dense thickets beneath groves of Phylica arborea Thouars (Rhamnaceae), which is one of the few trees native to the island (Wace and Holdgate 1958); 50–600 m. Additional Specimens Examined—TRISTAN DA CUNHA. Gough Island: slopes behind hut, above Glen Beach, [40°20’S, 10°0’W], 50 ft, 30 Nov 1955, Wace 12 (GH). Inacessible Island: Plateau at west end, [37°18′9”S, 12°40′28”W], 450 m, 26 Feb 1938, Christophersen 2545 (GH, O). [37°18′9”S, 12°40′28”W], s. d., Mosely et al. s. n. (GH); Base of Denstone Hill, [37°07’S, 12°17’W], ca. 400 m, 14 Oct 1989, Roux 2147 (NBG). Nightingale: At the peak, [37°07’S, 12°17’W], 300 m, 10 Feb 1938, Christophersen 2217 (O). Trail to lake region, [37°07’S, 12°17’W], 100 m, 12 Feb 1938, Christophersen 2232 (O); streambed along West Road to summit, [37°07’S, 12°17’W], ca. 300 m, Roux 2092 (NBG); Phylica forest near first pond, [37°07’S, 12°17’W], ca. 200 m, 20 Oct 1989, Roux 2193 (NBG). Tristan da Cunha: Above settlement, [37°07’S, 12°17’W], 600 m, 21 Dec 1937, Christophersen 23 (O); East of Big Point, [37°07’S, 12°17’W], 250 m, 29 Dec 1937, Christophersen 423 (O); Base of Round Hill, [37°07’S, 12°17’W], 650 m, 14 Jan 1938, Christophersen 1061 (O); Round Hill, [37°07’S, 12°17’W], 800 m, 14 Jan 1938, Christophersen 1093 (O); Up slope about 1 mi S of settlement, [37°07’S, 12°17’W], 600–1000 ft, 3 Jan 1937, Dyer 3554 (NY); [37°07’S, 12°17’W], without precise date, Keytel 4713 (NBG); [37°07’S, 12°17’W], 12 Nov 1852, Mac Gillivray 327 (GH); [37°07’S, 12°17’W], 12 Nov 1852, Mac Gillivray s. n. (NY); Above Soggy Plain, at tree limit, [37°07’S, 12°17’W], 18 Feb 1938, Mejland 1575 (O). Discussion—In addition to the type at P, a du Petit-Thouars collection at B is also annotated by Willdenow as type material (BGBM virtual herbarium, image ID: 260189, barcode: B-W 19721–01 0; Röpert 2000) but it is not clear that this collection should be regarded as such. Although some of du Petit-Thouars’ collections were distributed to B (Stafleu and Cowan 1976), the sheet in question does not bear a label indicating that it was in fact part of du Petit-Thouars’ herbarium. The status of the B specimen is critical though, because it is a different species, which we have identified as belonging to Pseudophegopteris. The protologue provided by du Petit-Thouars (1808) is brief and might pertain to either a species of Megalastrum or Pseudophegopteris. The provenance of the collection at B provides some evidence of the name’s application. Pseudophegopteris is not known from Tristan da Cunha (Christensen 1940; Holttum 1969, 1974; Tryon 1966; Wace and Holdgate 1958; Wace 1960, 1961), suggesting that the specimen at B was collected elsewhere and mislabeled. The B sheet is most likely P. aubertii (Desv.) Holttum, a species named by Desvaux in honor of du Petit-Thouars. Alternately, it could be 463 P. cruciata (Willd.) Holltum, a species that is doubtfully distinct from P. aubertii (Holttum 1974). After departing from Tristan da Cunha, du Petit-Thouars later traveled to Madagascar and the Mascarenes (Williams 2003) where P. aubertii is present. It seems likely that the specimen at B was collected there. Consequently, if the B material was not collected on Tristan da Cunha, then it is in conflict with the protologue. Considering these points and Recommendation 9A.5 of the ICBN (McNeill et al. 2006), we chose to designate the specimen at P as the lectotype for this species. An illustration of this species appears in Hemsley (1885, plate XXXIX) based on Carmichael s. n. (K, n. v.). The name Polypodium acunhianum Carmichael also appears in Hemsley (1885, p. 167), placed in synonymy, but Carmichael’s manuscript (K), was not validly published and the name therefore is considered nom. inval. Christensen (1940) and Tryon (1966) remarked on the similarity of Megalastrum aquilinum to M. spectabile from Chile and Argentina, and suggested long distance dispersal as a means to explain this apparent amphi-atlantic distribution. Morphologically, the plants have similar lamina cutting, densely pubescent axes provided with short erect hairs, brown lanceolate scales, and subglabrous to puberulent abaxial lamina surfaces between the veins. Megalastrum aquilinum differs from M. spectabile most notably by its entirely glabrous adaxial lamina surfaces, the presence of fugacious indusia (sometimes absent, see below), sparsely ciliate lamina margins with hairs that are often restricted to the proximal portions of the ultimate segments, thicker laminae, and recurved lamina margins. These last two characters, which were also cited by Christensen (1940), may be a response to wind damage, but are consistent in all of the material that we have seen. Christensen reported (1940) that he did not find an indusium in M. aquilinum. We have seen one specimen annotated by Christensen (Christophersen 2545), and confirm that it does not have any trace of an indusium, but all other specimens that we have seen do have small fugacious indusia (0.1–0.4 mm wide) bearing sessile glands and setae. Megalastrum glabrius (C. Chr. & Skottsb.) Sundue, Rouhan & R. C. Moran, stat. nov. Dryopteris inaequalifolia (Colla) C. Chr. var. glabrius [as “glabrior”] C. Chr. & Skottsb., C. Chr., Kongel. Dankse Vidensk. Selsk. Skr. Naturvidensk. Math Afd., ser. 8, 6: 74. 1920. Dryopteris inaequalifolia (Colla) C. Chr. f. glabrius [as “glabrior”] C. Chr. & Skottsb., in Skottsb., Nat. Hist. Juan Fernández 2: 19. 1920. Ctenitis inaequalifolia (Colla) Ching var. glabrius [as “glabrior”] (C. Chr. & Skottsb.) Kunkel, Nova Hedwigia 9: 261. 1965. Ctenitis inaequalifolia (Colla) Ching f. glabrius [as “glabrior”] R. A. Rodri., Duek & R. A. Rodr. Bol. Soc. Biol. de Conception 45: 148. 1972. Megalastrum inaequalifolium (Colla) A. R. Sm. & R. C. Moran var. glabrius [as “glabrior”] (C. Chr. & Skottsb.) R. A. Rodr., Gayana, Bot. 46: 10. 1989.—TYPE: CHILE. Juan Fernández, Masafuera, i Casas-dalen [valley of the Rio Casas], 11 Feb 1917, C. Skottsberg & I. Skottsberg 466 [as “446”] (lectotype here designated: UPS!; duplicate: BM!). Plants terrestrial, rhizomes not seen; petioles not seen; fronds 2-pinnate-pinnatifid medially, 3-pinnate-pinnatisect at the base, basal pinnae up to 60 cm long (estimated); medial pinnae 45 cm long, the base sessile, overlapping the rachis; pinnules 10 cm long, sessile, overlapping the pinna costa; pinna rachises with a reddish hue, abaxially nearly glabrous, sparsely glandular and sparsely pubescent, the hairs 0.3–0.4 mm 464 SYSTEMATIC BOTANY [Volume 35 Fig. 1. Detail of indument on three cicrumaustral Megalastrum species. A–E. Megalastrum peregrinum (Wace 133, GH) A. Abaxial costule and segments. B. Detail of scale. C. Detail of indument on abaxial costule. D. Adaxial costule and segments. E. Detail of hairs and glands on adaxial lamina surface. F–L. Megalastrum taafense (Jolinon 1071, P) F. Abaxial surface of pinnule and costule at the juncture with the pinna rachis. G. Detail of the hairs on the abaxial costule. H. Detail of hair from the abaxial costule. J. Abaxial lamina surface. K. Detail of scale from the pinna costa. L. Adaxial lamina surface. M–R. Megalastrum aquilinum (Christopherson 2545, GH) M. Abaxial surface of pinnule and costule at the juncture with the pinna rachis. N. Detail of indument upon abaxial lamina surface and veins. O. Detail of scale from pinna rachis. P. Adaxial lamina surface. Q. Detail of adaxial costule. R. Detail of indument from adaxial costule. 2010] Fig. 2. SUNDUE ET AL.: MEGALASTRUM IN CIRCUMAUSTRAL REGION 465 Distribution of the circumaustral species of Megalastrum. long, 2–4 celled, hyaline, the cross walls reddish, adaxially moderately puberulent, the hairs conspicuously short, 0.1–0.3 mm long, 1–3-celled, the cross walls reddish, the apices blunt; costules with a reddish hue, abaxially sparsely pubescent and scaly, the hairs 0.3–0.5 mm long, 2–4-celled, the scales 0.5–0.7 × 0.3–0.5 mm, ovate to lanceolate, gold-brown, translucent, entire, the cells isodiametric, adaxially moderately pubescent, the hairs 0.3–0.5 mm long, 3–4-celled; lamina tissue between the veins glabrous on both sides, abaxially glaucous, adaxially dark green; veins visible on both sides of the lamina, abaxially sparsely provided with appressed, filiform, uniseriate, reddish, scales, 0.2–0.4 mm long, adaxially glabrous; lamina margins glabrous; indusia present, 0.3–0.4 mm wide, brown, the margin ciliate, the cilia 0.2 mm long, the same color as the indusia. Figures 4A–C, 2, 5A. Etymology—From the Latin glabri-, glabrous, and the comparative suffix –or/-us, more so. The specific epithet glabrius refers to the absence of hairs on either side of the laminae and the lamina margins. Distribution and Ecology—Endemic to Isla Masafuera (Alexander Selkirk Island) of the Juan Fernández Islands where it is known with certainty only from Quebrada de las Casas. Specimens Examined—CHILE. Juan Fernandez Islands: Masafuera, without precise locality, 3 Mar 1920, Bryan s. n. (OSU); Masafuera Quebrada de las Casas, [33°46’S, 80°47’W], 28 Aug 1908, Skottsberg 731 (BM, UPS). Discussion—Megalastrum glabrius is known only from three fragmentary specimens, two of which were cited by Christensen (1920). The specimen at BM, collected by Skottsberg, does not have a collection number, but has the 466 SYSTEMATIC BOTANY [Volume 35 Fig. 3. Lamina dissection of three Megalastrum species. A. Megalastrum aquilinum (Christopherson 2545). B. Megalastrum peregrinum (Wace 133). C–D. Megalastrum taafense (C. Jolinon 1071, D. Aubert s. n.). 2010] SUNDUE ET AL.: MEGALASTRUM IN CIRCUMAUSTRAL REGION 467 Fig. 4. Detail of indument on two circumaustral Megalastrum species. A–C. Megalastrum glabrius (Skottsberg & Skottsberg 466, BM) A. Abaxial pinna rachis and pinnules at the juncture with the rachis of the lamian. B. Adaxial pinna rachis and pinnules. C. Detail of indument on adaxial pinna rachis. D. Megalastrum masafuerae (Solbrig et al. 3676, MICH), Abaxial pinna rachis and pinnules. same date and locality as Skottsberg 731 at UPS. Therefore, we consider it part of that collection. It should be noted that Skottsberg 731 bis at UPS, identified as M. inaequalifolium, has a different collection date and locality. In the original publication of the name Dryopteris inaequalifolia var. glabrius C. Chr. & Skottsb., the collection number “446” should be considered as a typographical error (instead of “466”), because the specimen cited by Christensen (1920) clearly corresponds to C. Skottsberg & I. Skottsberg 466: except the collection number, all of the other information on the label matches, and it bears the corrected identification annotated by Skottsberg. Megalastrum glabrius differs from its congeners by the absence of hairs on either side of the laminae and the lamina margins, the short-puberulent adaxial pinna rachises, and the ciliate-margined indusia. Also distinctive are the dark green color of the adaxial lamina surfaces, the glaucous abaxial surfaces, and the reddish axes. Megalastrum inaequalifolium (Colla) A. R. Sm. & R. C. Moran, Amer. Fern J. 77: 128. 1988. Polypodium inaequalifo- lium Colla, Mem. Reale Accad. Sci. Torino 39: 49–50. 1836; Herb. Pedem. 6: 228. 1836. Dryopteris skottsbergii C. Chr., Kongel. Danske Vidensk. Selsk. Skr. Naturvidensk. Math. Afd. ser. 8, 6: 15. 1920. Dryopteris inaequalifolia (Colla) C. Chr., Kongel. Danske Vidensk. Selsk. Skr. Naturvidensk. Math. Afd. ser. 8, 6: 74. 1920. Ctenitis inaequalifolia (Colla) Ching, Sunyatsenia 5: 250. 1940. Ctenitis inaequalifolia (Colla) Ching fo. inaequalifolia R. A. Rodri., in Duek & R. A. Rodr. Bol. Soc. Biol. de Conception 45:148. 1972.— TYPE: CHILE. Juan Fernández Island, “in sylvis umbrosis collium et montium Insulae Juan Fernández” Mar–May 1830, C. L. G. Bertero 1550 (lectotype here designated: P ex herb. Bory barcode: P00600449!; duplicates: BM-000890150!, NY!, P barcodes: P00600447!, P00600448!, P00600451!, P00600672!, WAG). Polypodium berteroanum Hook., Sp. Fil. 4: 269. 1862, non Spreng. 1827.—TYPE: CHILE. Juan Fernández Islands, “sylv. umbros. coll. Isl. Juan Fernández”, May 1830, Bertero 1660 (lectotype here designated: K, the sheet bearing the barcode: K000512194!; duplicate: K, a sheet labeled “1660(bis)”!, 468 SYSTEMATIC BOTANY Fig. 5. [Volume 35 Lamina dissection of two Megalastrum species. A. Megalastrum glabrius (Skottsberg 466). B. Megalastrum masafuerae (Skottberg 448). [without barcode]). Dryopteris villosa (L.) Kuntze var. berteroana (Hook.) C. Chr., Ark. Bot. 10(2): 13. 1910. Plants terrestrial; rhizomes not seen, reportedly forming erect trunks up to 1 m tall, 10 cm diam.; fronds 1.2–1.6 m long; petiole scales 3.50 × 0.25 cm, linear-lanceolate, brown, minutely denticulate, several layers of cells thick at the base, opaque or partially translucent distally; laminae 0.4–1.0 m long, 3-pinnate-pinnatisect; basal pinnae 22–50 cm long, inaequilateral; largest pinnules of the basal pinna 9.5–16.0 cm long, shortstalked to sessile; pinna rachises abaxially glandular, pilose, and with scattered scales, the glands sessile, yellow, hyaline, 0.1 mm wide, the hairs 1.0 mm long, hyaline, catenate, with reddish cross walls, 5- or 6-celled, the scales 1.5–2.0 × 0.3– 0.4 mm, lanceolate, light brown, translucent, entire, the cells elongate, adaxial pinna rachises densely pubescent, the hairs ca. 0.6 mm long, 5-celled, hyaline, catenate, antrorse; costules abaxially glandular, moderately pilose and with scattered scales, the glands sessile, yellow, hyaline, ca. 0.1 mm wide, the hairs ca. 1.0 mm long, hyaline, catenate, with reddish cross walls, 5- or 6-celled, the scales 0.4–0.6 × 0.2–0.5 mm, ovate, light brown, translucent, entire to erose, the cells isodiametric, adaxially densely pubescent, the hairs ca. 0.4 mm long, hyaline, catenate, antrorse; laminar tissue between the veins abaxially glabrous or provided with appressed uniseriate reddish scales, ca. 0.4 mm long, adaxially glabrous; veins visible on both sides of the laminae, abaxially glandular and moderately pilose, the glands sessile, yellow, hyaline, ca. 0.1 mm long, the hairs ca. 0.8 mm long, hyaline, composed of 6 cells, spreading, adaxially with scattered hairs along the midvein, the other veins glabrous, the hairs ca. 0.4 mm long, appressed; lamina margins ciliate, the hairs 0.5–0.7 mm long, 4–7-celled; indusia present or rarely absent, fugacious, ca. 0.2 mm wide, provided with (1)5–10 erect cilia, these ca. 0.5 mm long, and emerging from the center of the sorus in a tuft. Figures 6G –M, 2, 7C–D. Etymology—From the Latin inaequal-, uneven, unequal, dissimilar, and –folium, leaf, referring to the inaequilateral basal pinnae. Distribution and Ecology—Endemic to the Isla Masatierra (Robinson Crusoe Island) of the Juan Fernández Islands in the South Pacific Ocean; 215–660 m. Additional Specimens Examined—CHILE. Juan Fernandez Islands: Without locality or date, Bertero s. n. (P); Masatierra, subida al Mirador de Selkirk desde San Juan Bautista, [33°38’S, 78°51’W], 440 m, 27 Jan 1980, Marticorena et al. 9011 (OSU); Masatierra, Mirador de Selkirk, [33°38’S, 78°51’W], 575 m, 27 Jan 1980, Maticorena et al. 9026 (OSU); Masatierra, Quebrada de Villagra, Salto de La Pulga, [33°38’S, 78°51’W], 445 m, 28 Jan 1980, Marticorena et al. 9037 (MO, OSU); Masatierra, plazoleta del Yunque, [33°38’S, 78°51’W], 280 m, 2 Feb 1980, Marticorena & Ugarte 9082 (OSU); Masatierra, Cerro Pascua, [33°38’S, 78°51’W], 450 m, 8 Feb 1980, Marticorena et al. 9153 (OSU); Mas Atierra, Cerro Salsipuedas, [33°38’S, 78°51’W], 1,800 ft, 10 Dec 1965, Meyer 9499 (GH, MO); Mas Atierra, along trail to Comote, [33°38’S, 78°51’W], 1,000 ft, 25 Dec 1965, Meyer 9661 (GH, MO); s. d., Miller 119 (BM); Isla Mas Atierra, trail above Weber’s house on the way to the divide S of El Tranque, [33°38’S, 78°51’W], 400 m, 1 Mar 1939, Morisson 17326 (GH, US); Isla Robinson Crusoe, El Camote, [33°38’S, 78°51’W], 520 m, 21 Jan 1992, Ricci 402 (MO); At rd. to Portezuelo de Villagra, [33°38’S, 78°51’W], 215 m, 24 Dec 1954, Skottsberg & Skottsberg 12 (NY, S); Mas a Tierra, [33°38’S, 78°51’W], 250 m, 6 Dec 1916, Skottsberg & Skottsberg 65 (P, S, UPS); Mas a Tierra, Salsipuedes, [33°38’S, 78°51’W], 435 m, 20 Dec 1916, Skottsberg & Skottsberg 168 (S, UPS); Masatierra, oversta delen av Villagredalen, [33°38’S, 78°51’W], 500 m, 10 Jan 1917, Skottsberg & Skottsberg 274 (P, S, UPS, US); Masatierra, [33°38’S, 78°51’W], 500 m, 10 Jan 1917, Skottsberg & Skottsberg 275 (BM, P, S); Mas a Tierra, V. Colonial, Monte Maderugo, [33°38’S, 78°51’W], 24 Jan 1917, Skottsberg & Skottsberg 339 (S); Mas a Tierra, 2010] SUNDUE ET AL.: MEGALASTRUM IN CIRCUMAUSTRAL REGION 469 Fig. 6. Detail of indument on two circumaustral Megalastrum species. A–F Megalastrum spectabile (A–B Dusén s. n. NY; C–F Solomon & Solomon 4559, NY). A. Basal petiole. B. Basal petiole scale. C. Abaxial surface of pinna rachis and pinnae at the juncture of the rachis of the lamina. D. Detail of hairs on abaxial rachis of the lamina. E. Detail of hairs and scales on abaxial pinna costa. F. Adaxial surface of pinna rachis and pinnule. G–M Megalastrum inaequalifolium (G–H Meyer 9661, NY; J–M Skottsberg & Skottsberg 12, US) G. Basal petiole. H. Basal petiole scale. J. Abaxial pinna rachis and pinnules. K. Detail of hairs on abaxial pinna costa. L. Adaxial pinna rachis and pinnule. M. Detail of hairs on adaxial pinna costa. 470 SYSTEMATIC BOTANY [Volume 35 Fig. 7. Lamina dissection of two Megalastrum species. A–B. Megalastrum spectabile (A. Skottsberg 921, B. Hunnewell 15852). C–D. Meglastrum inaequalifolium (C. Skottsberg 420, D. Morisson 17326). 2010] SUNDUE ET AL.: MEGALASTRUM IN CIRCUMAUSTRAL REGION [33°38’S, 78°51’W], 22 Aug 1908, Skottsberg 721 (S); Mas a Tierra, Quebrada Salsipuedes, [33°38’S, 78°51’W], 660 m, 13 Jan 1917, Skottsberg & Skottsberg 1151 (S, UPS); Masatierra, Valle Colonial, [33°38’S, 78°51’W], 22 Aug 1908, Skottsberg 731 bis (UPS); Mas a Tierra, Salto de Pangal, [33°38’S, 78°51’W], 180 m, 25 Oct 1955, Sparre 75 (S); Masatierra, on path from pueblo San Juan Bautista to Mirador Selkirk, [33°38’S, 78°51’W], 480 m, 28 Jan 1980, Stuessy & Saunders 5014 (OSU); Masatierra, Cerro Agudo, down into second valley on Villagra side, [33°38’S, 78°51’W], 630 m, 12 Feb 1990, Stuessy et al. 11644 (OSU); Masatierra, Puerto Frances, up the ridge W of the ascent ridge, then down into the forest and across in La Piña, [33°38’S, 78°51’W], 590 m, 23 Jan 1991, Stuessy & Crawford 11963 (OSU); Masatierra, up from La Plazoleta del Yunque on trail to La Carbonera de Torres, [33°38’S, 78°51’W], 440 m, 28 Jan 1991, Stuessy & Soto 12055 (OSU); Masatierra, down from top of cerro (ridge up from Centinela) into quebrada toward the Corrales de Molina, [33°38’S, 78°51’W], 640 m, 30 Jan 1991, Stuessy & Crawford 12129 (OSU); Masatierra, Valle Villagra, below Cerro Agudo, [33°38’S, 78°51’W], 350 m, 24 Jan 1997, Stuessy et al. 15396 (WU). Discussion—Colla appears to have published the name Polypodium inaequalifolium in two places at nearly the same time, Herb. Pedem. 6: 228. 1836, and Mem. Reale Accad. Sci. Torino 39: 49. 1836. According to TL-2 (Stafleu and Cowan 1976), Herb. Pedem 6 was received between November and December of 1836. A date which volume 39 of the Mem. Reale Accad. Sci. Torino was received by libraries is not known, but it has come to our attention that the Memoire was in fact read by Colla to the society during a meeting on the 29th of November 1835. A copy of volume 39 at the library of the Accademia della Scienze in Torino attests to this with an inscription on the inside cover that reads “exhibitus die 29 novembris 1835,” but according to article 29.1 of the ICBN, effective publication would require that a pamphlet also be distributed at the time of the reading (McNeill et al. 2006). Megalastrum inaequalifolium is distinguished by massive trunk-forming rhizomes (reportedly up to 1 m tall, 10 cm diam.), large petiole scales (3.50 × 0.25 cm), pilose pinna rachises (the hairs 1.0 mm long), veins of the abaxial lamina surfaces with hairs 0.8 mm long, ciliate lamina margins (the hairs 0.5–0.7 mm long), and fugacious indusia. The latter appear as (1)5–10 erect cilia (0.5 mm long) that emerge as a tuft from the center of the sorus. Indusia are often missing in mature sori, and in some cases apparently absent altogether. The type of Megalastrum inaequalifolium (Bertero 1550) is a mixed collection. Another sheet of this number at BM (no. 000890149) is M. spectabile. Hooker’s syntypes for Polypodium berteroanum included both M. inaequalifolium, M. spectabile (Chile, 1831, Anderson s. n. K), and what is most likely M. pleiosorus (Hook. f.) C. V. Morton from the Galapagos Islands (n.v.). The lectotype chosen here agrees with Christensen’s (1913) application of that name as a synonym of M. inaequalifolium. Megalastrum masafuerae Sundue, Rouhan & R. C. Moran, sp. nov.—TYPE: CHILE. Juan Fernández Islands, Masafuera, Quebrada Vacas, on slopes of canyon among Myrceugenia, between rocks, about 60–90 cm tall, no trunk, near brook, rare, 28 Nov 1965, O. T. Solbrig, H. E. Moore Jr., & J. Walker 3676 (holotype: GH!; isotypes: MICH!, US!). A Megalastro inaequalifolio indusiis majoribus et lamina margine breviter ciliata laminae differt. Plants epipetric; rhizomes not seen, reportedly not forming erect trunks; leaves ca. 1.2 m long; scales of the petiole base 1.5–2.0 × 0.20–0.35 cm, linear-lanceolate, entire, brown, lustrous, the cells isodiametric to elongate; laminae ca. 0.6 m long, 3-pinnate-pinnatifid at base, 2-pinnate-pinnatisect medially; basal pinnae 35–55 × 40 cm, inaequilateral; pinnules short-stalked to sessile, the largest pinnule of the basal pinnae 471 20 cm long; pinna rachises abaxially sparsely-glandular, sparsely scaly and sparsely pubescent, the scales and hairs slightly more abundant distally, the glands short-stipitate, ca. 0.1 mm long, hyaline, the scales 3.0–4.5 × 0.5–0.6 mm, linearlanceolate, slightly bullate, lustrous, light brown, entire, the cells elongate, the hairs 0.4–0.8 mm long, 3–6-celled, acicular, antrorse, hyaline with reddish cross-walls, the rachises adaxially nonglandular, without scales, densely pubescent, the hairs like those of the abaxial surface; costules on the abaxial surface nonglandular, sparsely pubescent and sparsely to moderately scaly, the hairs like those of the rachises, the scales 0.6–2.0 × 0.2–1.0 mm, ovate, gold-brown, translucent, slightly iridescent, the cells mostly isodiametric, the apices acute or filiform, the filiform portion up to 0.5 mm long when present, the margins erose to entire, sometimes with a few broad teeth or cilia up to 0.2 mm long, adaxially moderately pubescent, the hairs erect to spreading, otherwise similar to those of the abaxial rachises; lamina tissue between the veins abaxially and adaxially glabrous; veins visible on both sides of the lamina, the veins glabrous adaxially, abaxially the larger veins sparsely pubescent, the hairs 0.5 mm long, 4-celled, smaller veins moderately provided with 0.2–0.7 mm long, nonglandular, erect, reddish, filiform, scales, these uniseriate or rarely bifurcating; lamina margins sparsely ciliate, the hairs restricted to proximal portions of the pinnules, the hairs 0.3 mm long, 3-celled; indusia present, 0.4–0.8 mm wide, brown, often folded or lost in mature sori, the margins sparsely ciliate, the cilia 0.1–0.2 mm long, brown. Figures 4D, 2, 5B. Etymology—The specific epithet is derived from the original name given to Alexander Selkirk Island, Isla Masafuera. Distribution and Ecology—Endemic to the Isla Masafuera (Alexander Selkirk Island) in the Juan Fernández Islands in the South Pacific Ocean, known only from the Valley of Quebrada de las Vacas and North branch of the Quebrada Varadero. Additional Specimens Examined—CHILE. Juan Fernandez Islands: Masafuera, North branch of Quebrada Varadero, at the first waterfall, [33°46’S, 80°47’W], 100 m, 3 Feb 1986, Ruiz & Landero 8265 (OSU); Masafuera, Quebrada de los Vacas, [33°46’S, 80°47’W], 10 Feb 1917, Skottsberg & Skottsberg 448 (S). Discussion—Megalastrum masafuerae is distinguished by large indusia (0.4–0.8 mm wide) with sparsely ciliate margins, axes and veins sparsely pubescent abaxially, and nearly glabrous lamina margins with marginal hairs (if any) restricted to the proximal portions of the sinuses. Megalastrum glabrius, also endemic to Isla Masafuera, is indusiate, but its indusia are smaller (0.3–0.4 mm wide). Furthermore, it lacks hairs on the laminae and has puberulent adaxial axes. Megalastrum inaequalifolium on Isla Masatierra also has indusia, but it differs by the indusia being fugacious, smaller (ca. 0.2 mm wide), and bearing (1)5–10 erect acicular hairs, as well as by its pilose axes and evenly ciliate lamina margins that are provided with 0.5–0.7 mm long hairs. Megalastrum peregrinum Sundue, Rouhan & R. C. Moran sp. nov.—TYPE: TRISTAN DA CUNHA. Gough Island, southern end of Gonydale, frequent between boulders in sheltered hollows and crevices, 1,600 ft., 12 Feb 1956, N. M. Wace 133 (holotype: GH!). A Megalastro aquilino laminae pagina adaxiali supra dense pubescenti et glandulosa differt. Plants terrestrial; rhizomes erect, ca. 1.5 cm wide; fronds 0.35–1.00 m long; basal petiole scales 3.0 × 0.1–0.15 cm, linear-lanceolate, light brown, translucent, minutely denticulate, 472 SYSTEMATIC BOTANY twisted, the cells elongate; laminae 30–60 cm long, 3-pinnate at base, 2-pinnate-pinnatifid medially; basal pinna 12–22 cm long, inaequilateral, short-stalked; pinnules sessile, the basal segments frequently overlapping the pinna rachis, the largest pinnule of the basal pinna 7–9 cm long; pinna rachises abaxially glandular, scaly, and densely pubescent, the glands sessile, globose, 0.1 mm long, the hairs 0.2–0.4 mm long, 3- or 4-celled, hyaline, acicular, the cross walls reddish, the scales 1.5–4.0 × 0.4–1.2 mm, ovate to lanceolate, translucent, light brown, slightly bicolorous, the center darker than the edges, entire, the cells isodiametric, adaxial pinna rachises not seen; costules abaxially glandular, scaly, and pubescent, the glands like those of the costae, the scales 1.5–2.5 × 0.5 mm, ovate to lanceolate, the apices attenuate, up to 1/3 the length of the scale, otherwise similar to those of the pinna rachises, the hairs similar to those of the abaxial costae, adaxial costules not seen; lamina tissue between the veins abaxially glandular and sparsely pubescent, the glands sessile, globose, 0.1 mm long, the hairs 0.2–0.3 mm long, 2-celled, erect, adaxially glandular and pubescent, the glands sessile, globose, 0.1 mm long, the hairs 0.3–0.5 mm long, 3- or 4-celled, spreading; veins not visible on either side of the lamina, abaxially glandular, pubescent, and provided with scales along the main vein, the hairs 0.3–0.5 mm long, 3- or 4-celled, adaxially pubescent, the hairs like those between the veins; lamina margins recurved, ciliate, the hairs 0.2–0.4 mm long, 2- or 3-celled, acicular; indusia present, 0.3–0.4 mm wide, light brown, fugacious, the surface and margins with sessile glands, ca. 0.1 mm long, and sometimes with 1 or 2 setae, ca. 0.1 mm long; spores echinate (Tryon and Lugardon 1990: 460 as Ctenitis aquilina). Figures 1A–E, 2, 3B. Etymology—From the Latin peregrinus, foreign, having a tendency to wander. Referring to the ancestor of this species that must have wandered to these remote islands from South America. Distribution and Ecology—Endemic to Gough Island in the South Atlantic Ocean, which is part of the Tristan da Cunha archipelago; among rocks, on banks, in the open, or under stands of Phylica arborea ca. 55–500 m. Additional Specimens Examined—TRISTAN DA CUNHA. Gough Island: Transvaal Bay, damp area below Phylica trees, growing on moss bank, 40°21’S, 9°53’W, 22 Oct 1989, Cooper G89053 (NBG); Snoek Gat., tussock grassland and fernbush, [40°20’S, 10°0’S], 22 March 2000, Hänel & Jones CH 021 (NBG); Under Phylica arborea north-west of base, 40°S, 9°W, 55 m, 31 Oct 1979, Roux 716 (NBG). Discussion—Megalastrum peregrinum is distinguished from all other species in the circumaustral region by the lamina tissue between the veins adaxially pubescent and glandular. In other aspects, M. peregrinum is similar to M. spectabile of Chile and Argentina, M. aquilinum of Tristan da Cunha and Gough Islands, and M. taafense of Île Amsterdam and Île Saint-Paul. In addition to the indument of the adaxial laminae, it differs from M. spectabile in having recurved lamina margins, a fugacious indusia, and longer scales (1.5–2.5 mm long vs. 0.5–1.2 mm long) on the abaxial costules, and from M. aquilinum and. M. taafense by the adaxial indument, and having more densely ciliate lamina margins and longer scales (1.5–2.5 mm long vs. 1.0–1.5 mm long) on the abaxial costules. The South Atlantic islands of the Tristan archipelago, including Tristan da Cunha, the Nightingale group, Inaccessible, and Gough Island, are about 1,750 miles west of South Africa and 2,088 miles east of South America. Gough Island lies 230 miles southeast of the other islands in the Tristan da Cunha archipelago. All the islands are of recent [Volume 35 volcanic origin, with ages of one million years (Tristan), six million years (Gough), eight million years (Inaccessible), and 16 million years (Nightingale group) (Wace and Dickson 1965). The islands have a temperate flora that is low in diversity, but rich in ferns. About half of the vascular plant diversity is comprised of ferns and lycophytes (Christensen 1940; Tryon 1966; Wace and Holdgate 1958). The islands’ flora is notable for its high endemism: at least half of its species or varieties of ferns and lycophytes are endemic (Christensen 1940; Tryon 1966). The addition of M. peregrinum brings the number of ferns and lycophyte species in the island group up to 34. Based on the young age of the Tristan da Cunha archipelago and the similarity of M. peregrinum to the South-American M. spectabile, an allopatric origin of this species through long-distance dispersal from South America is likely. A similar long-distance dispersal event has been inferred for several species in the “ciliatum group” of Elaphoglossum on Tristan da Cunha (Vasco et al. 2009). Alternatively, M. peregrinum might have evolved locally on the islands from M. aquilinum, to which it is perhaps even more similar morphologically. Megalastrum spectabile (Kaulf.) A. R. Sm. & R. C. Moran, Enum. Filic. 121. 1824. Polypodium spectabile Kaulf., Enum. Fil.: 121. 1824. Phegopteris spectabilis (Kaulf.) Fée, Mém. Foug. 5 Gen. Filic. 243. 1852. Dryopteris spectabilis (Kaulf.) C. Chr., Kongel. Dankse Vidensk. Selsk. Skr. Naturvidensk. Math. Afd., ser. 8, 6: 69. 1920. Ctenitis spectabilis (Kaulf.) Kunkel, Nova Hedwigia 13: 333. 1967.— TYPE: CHILE. 1827, L. A. von Chamisso s. n. (lectotype, chosen by Christensen (1920): P!). Polypodium contractum Desv. Mém. Soc. Linn. Paris 6: 242. 1827.—TYPE: CHILE. “habitat in regno Chilense,” no date, collector unknown, s. n. (holotype: P!, herb. Desvaux). Dryopteris spectabilis (Kaulf.) C. Chr. var. philippiana C. Chr., Kongel. Danske Vidensk. Selsk. Naturvidensk. Math. Afd., ser. 8, 6: 70. 1920. Ctenitis spectabilis (Kaulf.) Kunkel var. philippiana (C. Chr.) R. A. Rodr., in Duek et R. A. Rodr., Bol. Soc. Biol. Concepción 45: 148. 1972. Megalastrum spectabile (Kaulf.) A. R. Sm. & R. C. Moran var. philippianum (C. Chr.) A. R. Sm. & R. C. Moran.—TYPE: CHILE. Valdivia, Krause s. n. (lectotype here designated: NY!). Plants terrestrial; rhizomes not forming erect trunks; fronds up to 1.4 m long; petiole scales 1.0–2.2 × 0.06–0.15 cm, linearlanceolate, gold-brown, sparsely and minutely denticulate, the base of the scale thickened and curved immediately above the point of attachment, the apices filiform, somewhat tortuous, the cells elongate; laminae 35–60 cm long, 2-pinnate-pinnatisect to 3-pinnate-pinnatifid at the base, 2-pinnate-pinnatifid medially; basal pinnae (12)22–28(52) cm long, inaequilateral; pinnules short-stalked to sessile, the largest pinnule of the basal pinna 9–11 cm long; pinna rachises sparsely glandular, densely pubescent and moderately scaly both abaxially and adaxially, the glands ca. 0.1 mm long, sessile, hyaline, yellowish, the hairs 0.3–0.5 mm long, 2–5-celled, acicular, hyaline, spreading, the scales 0.8–3.5 × 0.2–0.6 mm, lanceolate, brown, lustrous, entire to erose, the cells elongate; costules abaxially sparsely glandular, densely pubescent and moderately scaly, the glands ca. 0.1 mm long, sessile, hyaline, yellowish, the hairs 0.1–0.5 mm long, 1–5-celled, acicular, hyaline, spreading, the scales 0.5–1.2 × 0.1–0.2 mm, lanceolate, brown, adaxially pubescent, the hairs like those of the abaxial side; laminar tissue between the veins abaxially glabrous to puberulent, 2010] SUNDUE ET AL.: MEGALASTRUM IN CIRCUMAUSTRAL REGION the hairs erect 0.3 mm long, also provided with appressed 0.4 mm long reddish uniseriate proscales, adaxially glabrous to sparsely pubescent, the hairs ca. 0.3 mm long, 3- or 4-celled; veins visible on the abaxial side of the lamina, abaxially moderately pubescent and glandular, the hairs 0.2–0.7 mm long, erect, the glands sessile, yellow, hyaline, adaxially sparsely pubescent to moderately pubescent, the hairs 0.3–0.7 mm long, appressed; lamina margins ciliate, the hairs 0.3–0.4 mm long, 3–4-celled; indusia absent. Figures 6A–F, 2, 7A–B. Etymology—From the Latin spectabilis, spectacular, showy. Distribution and Ecology—Chile, Argentina, restricted to Valdivian temperate rain forests; 10–350(–500) m. Specimens Examined—ARGENTINA. Chubut: Lago [illeg.], 2 Feb 1945, Castellanos 114252 (NY). Neuguen: Lago Espejo, 40°37’S, 71°45’W, 20 Mar 1939, Cabrera 5037 (GH). Rio Negro: Neuguen, Lago Nahuel Huapi, Puerto Manzano, 41°0’S, 71°30’W, 12 Mar 1963, de la Sota 2799 (MICH); Bariloche, Puerto Blest Area, west end of Lago Nahuel Huapi, 41°0’S, 71°30’W, 5 Nov 1982, Sage s. n. (UC). Unknown: s. d., Weiland s. n. (S). CHILE. Aisen: Patagonia occidental, Rio Aisen [Aysen], 26 jan 1897, Dusen s. n. (BM, S); Patagonia occidental, [45°24’S, 72°42’W], 15 Jan 1897, Dusen s. n. (NY); Puerto Aisen, [45°24’S, 72°42’W], 17 Feb 1945, Looser 5062 (GH). Araucania: Temuco, [38°45’S, 72°40’W], 5 Feb 1906, anon. s. n. (BM); Temuco, [38°45’S, 72°40’W], Jan 1919, Claude-Joseph 885 (US); Cautin, Llaima, 38°42’S, 71°46’W, 25 Jan 1925, Claude-Joseph 3046 (US); Melleco, Angol, Parque Nacional Contemo, [38°0’S, 70°52’W], 24 Apr 1970, de la Sota 6011 (NY); Lota, [37°5′S, 73°10’W], 5 Mar 1877, Savatier 272 (P); Cautin, Temuco, Cerro Nielol, 38°44’S, 72°40’W, 350 m, 27 Nov 1947, Wall & Sparre 3240 (S). Biobio: Concepción, 37°5′S, 73°15’W, s. d., anon. 156 (K); Concepción,Talcahuano, Parque Hualpen, 36°46’S, 73°6’W, 21 Apr 1970, de la Sota 6028 (US); Concepción, Valparaiso, [37°5′S, 73°15’W], s. d., Gaudichaud 34 (P); Concepción, [37°5′S, 73°15’W], 1841, Hombron s. n. (GH); Concepción, quebrada on Avenida Alemana, 18 Feb 1951, Junge 2924 (US); Concepción, Collin, cerca de Tome, 36°37’S, 72°57’W, 24 Jul 1934, Looser s. n. (US); Concepción, Talcahuano, 36°43’S, 73°7’W, Apr 1868, Poeppig 45 (P); Arauco, Contulmo, 38°0’S, 73°14’W, 16 July 1975, Zollner s. n. (NY). Coquimbo: Coquimbo, 8 Feb 1948, Files 574 (S); Ovalle, Bosque de Talinay, [30°35’S, 71°12’W], 500 m, 8 Oct 1947, Sparre 2948 (S). Los Lagos: Valdivia, Quitalito, [39°48′50”S, 73°14′45”W], 23 Mar 1931, anon. 1430.4 (GH); Valdivia, [39°48′50”S, 73°14′45”W], s. d., Buchtien s. n. (S); Valdivia, [illeg.], [39°48′50”S, 73°14′45”W], 15 Apr 1904, Buchtien s. n. (S); Valdivia, [39°48′50”S, 73°14′45”W], 1906, Buchtien s. n. (S); Valdivia, [39°48′50”S, 73°14′45”W], 15 Feb 1904, Buchtien s. n. (BM); Valdivia, Corral, [39°48′50”S, 73°14′45”W], 8 Jul 1930, Gunkel 2467 (GH); Llanguihue, Puerto Varas, 41°19’S, 72°59’W, Feb 1926, Gunther & Buchtien 13 (S); Valdivia, [39°48′50”S, 73°14′45”W], 200 m, Mar 1925, Hollerymayer 693 (B, BM, F, GH, MO); Panguipulli, [39°38′40”S, 72°19′50”W], s. d., Hollerymayer 156c (B); Llanguihue, Peulla, 41°19’S, 72°59’W, 2 Jan 1939, Hunnewell 15852 (GH); Chiloe, Piruquina, [42°28’S, 73°48’W], 17 Dec 1931, Junge 84 (107) (MO); Llanquihue, Casa Pangue, 41°3′S, 71°52’W, Dec 1926, Shannon & Shannon 31 (US); Chiloe, 42°17’S, 73°40’W, 26 Jul 1908, Skottsberg 921 (S); Chiloe, vid mynningen af Rio Pudeto, [42°28’S, 73°48’W], 16 Jul 1908, Skottsberg s. n. (UPS); Chiloe, W of rt. 5 ca. 5 km past Coipomo, ca. 20 km S of Ancud, 41°52’W, 73°50’W, 80–100 m, 15 Jan 1981, Sobel & Strudwick 2738 (NY); Valdivia, Corral, Quebrada La Aguada, [39°48′50”S, 73°14′45”W], 10 m, 3 Feb 1979, Solomon & Solomon 4559 (MO); Osorno, Puyehue, [40°34’S, 73°09’W], 15 Jan 1947, Sparre 2131 (S, US); Osorno, Puyehue, [40°34’S, 73°09’W], 15 Jan 1947, Wall s. n. (NY); Osorno, Puyehue, [40°34’S, 73°09’W], s. d., Wall & Sparre 9 (S). Los Rios: Southern Corral, [39°48′50”S, 73°14′45”W], 15 Feb 1907, anon. s. n. (S); [Valdivia], [39°48′50”S, 73°14′45”W], s. d., Bridges 806 (BM, K); Valdivia [illeg.], [39°48′50”S, 73°14′45”W], 15 Feb 1904, Buchtien s. n. (US); Valdivia, Casilla, [39°48′50”S, 73°14′45”W], 1904, Buchtien s. n. (US); Valdivia, Panguipulli, 38°48’S, 71°57’W, 200 m, July 1926, Hollerymayer 1933 (MO, US, S); Valdivia, [39°48′50”S, 73°14′45”W], 1854, Lechler 501 (BM, K, P, S, UPS); Valdivia, [39°48′50”S, 73°14′45”W], s. d., Philippi s. n. (K, P). Unknown: s. d., anon. s. n. (F); Jan 1919, Claude-Joseph 884 (US); Jan 1921, Claude-Joseph 2660 (US); [illeg.], Dec 1928, Claude-Joseph 5853 (US); 3 Jun 1897, Dusen s. n. (S); s. d., Gay s. n. (P); Southern Chile, s. d., Philippi s. n. (K); 1 Feb 1940, Schwabe 6 (NY). Discussion—As originally described, the name P. spectabile Kaulf. was applied to plants from throughout the western hemisphere, with syntypes that included two other 473 species, M. caribeum (Funk & Schlim 282, Moritz 202 pp) and M. subincisum (Funck & Schlim 1575, Moritz 202). By chosing the Chamisso collection as a type, Christensen restricted the application of the name. Length and distribution of pubescence is variable in Megalastrum spectabile, with specimens ranging from glabrous to puberulent on the lamina surfaces between the veins abaxially. The length of hairs upon the veins also varies in these plants, abaxially ranging from 0.2–0.7 mm long, and adaxially ranging from 0.3–0.7 mm long. Longer haired plants have been recognized as M. spectabile var. philippiana, which Christensen described as being smaller, more coriaceous, more densely scaly, and having subulate whitish hairs intermixed with the shorter hairs. While none of Christensen’s characters reliably distinguish var. philippiana, it can be identified by being glabrous between the veins abaxially, and by having slightly longer hairs on the veins abaxially (0.5–0.7 mm long). By comparison, var. spectabile is identified by the puberulent lamina tissue between the veins abaxially (the hairs 0.3 mm long, erect), and relatively shorter hairs on the veins abaxially (0.2–0.6 mm long). We find that the variation in pubescence between these varieties is part of a continuum with numerous intermediates, and not worthy of recognition. Megalastrum spectabile is restricted to the Valdivian temperate rainforests of Chile and neighboring Argentina. Most collections have been made between 36°–42° deg. S, with one (Sparre 2948) at 30° S, outside of Ovalle, in the Región de Coquimbo, where northern relictual pockets of Valdivian forest occur. Megalastrum taafense Rouhan, Sundue & R. C. Moran, sp. nov.—TYPE: TERRES AUSTRALES ET ANTARCTIQUES FRANÇAISES. Nouvelle Amsterdam, dans une voûte d’une coulée, ombragée, 12 Jul 1963, A. Lourteig & P. Cour 50 (holotype: P!). A Megalastro aquilino lamina adaxialiter glabra abaxialiter inter venas glabra differt. Plants terrestrial, rhizomes erect, 2.7 cm diam., not forming large erect trunks, the scales 35.0 × 1.0–1.5(–2.3) mm, linear lanceolate, thin, brown, translucent, irregularly twisted, subentire, bearing few teeth distally; fronds up to 80 cm long, petioles sulcate; petiole bases scaly with scales similar to those of the rhizome, but shiny dark brown; laminae up to 41 cm long, lanceate to triangular; 2-pinnate-pinnatisect (rarely tripinnate) at base, 2-pinnate-pinnatifid to 2-pinntate-pinnatisect medially; basal pinnae up to 23 cm long, short-stalked, the stalk up to 1.5 cm long, slightly to strongly inequilateral with the basal basiscopic pinnules more elongate, the most basal basiscopic pinnules (to 15 cm long) 1.4–2.3 times the length of the most basal acroscopic ones, the pinnules on the acroscopic side not or only slightly reduced toward the base of the pinnae; pinnules sessile, the basal segments frequently overlapping the pinna rachis; rachises and pinna rachises puberulent to densely pubescent on both surfaces, nonglandular, the hairs erect, 0.2–0.5 mm long, to 5-celled, sparsely scaly, the scales up to 4.0 × 1.0 mm, lanceolate, entire, flat (nonbullate), shiny dark brown with clearer margins; costules abaxially pubescent, non-glandular, the hairs erect to spreading, 0.2–0.5 mm long, to 5-celled, sparsely scaly, the scales similar to those of the pinna rachises but shorter, 1.5 × 0.5 mm, adaxially puberulent to pubescent, nonglandular, the hairs erect to somewhat antrorse, 0.2–0.5 mm long; laminar tissue between veins glabrous on both surfaces; veins 3–6 pairs per 474 SYSTEMATIC BOTANY pinnule lobe, visible on both surfaces, abaxially pubescent and sparsely glandular, the hairs erect, 0.2–0.5 mm long, usually 2–5-celled, the glands spherical, clear yellowish, shiny, short-stalked, ca. 0.1 mm diam., 1–2-celled, adaxially glabrous; lamina margins slightly recurved, sparsely ciliate, the cilia 0.3 mm long, 2- or 3-celled, fugacious indusia present, inconspicuous, 0.1–0.3 mm wide, provided with ca. 0.1 mm long sessile glands, and sometimes with 1–4 ca. 0.1 mm long setae. Figures 1F–L, 2, 3C–D. Etymology—From ‘TAAF’, the French acronym for the Territory of the French Southern and Antarctic Lands (French: ‘Terres Australes et Antarctiques Françaises’). Amsterdam and Saint-Paul Islands, where the species is endemic, belong to this Territory. Distribution and Ecology—Amsterdam and St-Paul Islands, South Indian Ocean. Terrestrial in gullies, in shade of lava crevices and caves; observed along river and waterfall. Plants isolated, rare, 50–350 m. Additional Specimens Examined—TERRES AUSTRALES ET ANTARCTIQUES FRANÇAISES. Amsterdam Island: Caverne des Venus(?) de Verre(?), [37°50’S, 77°30’E], 20 Mar 1960, Aubert s. n. (P); [37°50’S, 77°30’E], 20 Mar 1960, Aubert s. n. (P); Au bord d’une cavité, près du camp, [37°50’S, 77°30’E], 31 Mar 1958, Cour s. n. (P); Au dessus du bois de Phylica, direction le Fourneau, [37°50’S, 77°30’E], 200–300 m, 27 Dec 1984, Jolinon 891 (P); Au dessus du bois de Phylica, direction le Fourneau, [37°50’S, 77°30’E], 200–300 m, 27 Dec 1984, Jolinon 892 (P); Entrecasteaux, rivière à 700 m de la baraque, [37°50’S, 77°30’E], 50 m, 3 Jan 1985, Jolinon 933 (P); Le Grand Tunnel, coulée, [37°50’S, 77°30’E], 110 m, 8 Jan 1985, Jolinon 938 (P); Versant des Taureaux Sauvages, [37°50’S, 77°30’E], 332 m, 23 Jan 1985, Jolinon 1016 (P); Del Cano, dans la Ravine le long de la cascade, [37°50’S, 77°30’E], 160 m, 27 Jan 1985, Jolinon 1068 (P); Deal Cano, dans la Ravine le long de la cascade, [37°50’S, 77°30’E], 160 m, 27 Jan 1985, Jolinon 1071 (P); De la coulée Heurtin au Faux Sommet, [37°50’S, 77°30’E], 250 m, 4 Feb 1985, Jolinon 1101 (P); Mêmes endroits que les deux numéros précédents, [37°50’S, 77°30’E], 23 Dec 1974, L’Isle 28 (P); [37°50’S, 77°30’E], 12 Dec 1963, Lourteig & Cour 50 (P); Vallée entre les 2 Venus, [37°50’S, 77°30’E], 350 m, 16 Dec 1963, Lourteig & Cour 78 (P); [37°50’S, 77°30’E], 1 Jan 1962, Noël 29 (P). Saint-Paul Island: [38°43’S, 77°31’E], 11 Nov 1974, L’Isle 3 (P). Discussion—Given some known mistakes in the labels by L’Isle, Tardieu-Blot (1954) postulated that this taxon, treated by her as Dryopteris aquilina (Thouars) C. Chr., had been erroneously recorded from Amsterdam. Several recent and annotated collections attest the presence of this taxon on Amsterdam. The presence of this species on St. Paul however is still based on a single collection (L’Isle 3). Until more recent collections can be made, some doubt remains as to the presence of the taxon on that Island. Megalastrum taafense resembles M. aquilinum from Tristan da Cunha in the cutting of the laminae, revolute margins, and fugacious indusia. However, M. taafense differs by having shorter hairs on the abaxial costules, and glabrous lamina tissue between the veins abaxially. It also lacks glands adaxially, whereas M. aquilinum sometimes has sessile spherical glands near the adaxial costae. The brown, nonbullate scales of the abaxial surfaces of the laminae, and the laminar surfaces glabrous between veins on both surfaces easily distinguish Megalastrum taafense from the three geographically closest tropical taxa: M. lanuginosum (Africa, Madagascar, Mascarene Islands, Comoros), M. canacae (Mauritius and La Réunion), and M. lanatum (La Réunion). Acknowledgments. We would like to thank the curators of the following herbaria for providing loans of material: B, BM, F, GH, K, MICH, NY, MO, NBG, O, OSU, P, S, UC, UPS, US, WU. We would like to thank Alan Smith for discussions regarding Pseudophegopteris. Roy Gereau assisted with Latin diagnoses. We are thankful to Elena Borgi from the Accademia delle Scienze, Torino, for providing us with information about [Volume 35 publications of the Accademia. Harutu Fukuda prepared the illustrations. Alejandra Vasco assisted with the preparation of the manuscript. This study was funded by a grant to Moran from the United States National Science Foundation (DEB 0717056). Literature Cited Christensen, C. 1913. A monograph of the genus Dryopteris, Part I. The tropical American pinnatifid-bipinnatifid species. Kongelige Danske Videnskabernes Sselskabs Skrifter. Naturvidenskabelige og Mathematiske Afdeling, ser. 7, 10: 55–282. Christensen, C. 1920. A monograph of the genus Dryopteris, Part II. The tropical American bipinnate-decompound species. Kongelige Danske Videnskabernes Sselskabs Skrifter. Naturvidenskabelige og Mathematiske Afdeling, ser. 8, 6: 3–132. Christensen, C. 1931. Asiatic pteridophyta collected by Joseph F. Rock. Contributions from the United States National Herbarium 26: 265–337. Christensen, C. 1940. The pteridophytes of Tristan da Cunha. In Results of the Norwegian scientific expedition to Tristan da Cunha 1937–1938, ed. E. Christophersen, 6: 1–25. Du Petit-Thouars, L.-M. A. 1808. Esquisse de la flore de l’Isle de Tristan d’Acugna. Paris. Hemsley, W. B. 1885. Report on the botany of the Bermudas and various other islands of the Atlantic and southern oceans, 2nd part. Report on the Scientific Results of the Voyage of H. M. S. Challenger during the years 1873–76: under the command of Captain George S. Nares and the late Captain Frank Tourle Thomson. Prepared under the superintendence of Sir C. Wyville Thomson and John Murray. Botany. London. Holttum, R. E. 1969. Studies in the family Thelypteridaceae. The genera Phegopteris, Pseudophegopteris, and Macrothelypteris. Blumea 17: 1–32. Holttum, R. E. 1974. Thelypteridaceae of Africa and adjacent islands. Journal of South African Botany 40: 123–168. Manton, I. and G. Vida. 1968. Cytology of the fern flora of Tristan da Cunha. Proceedings of the Royal Society of London. Series B. Biological Sciences 170: 361–379. Marticorena, C. and R. Rodríguez (eds.). 1995. Flora de Chile 1. Universidad de Concepción: Concepción. McNeill, J., F. R. Barrie, H. M. Burdet, V. Demoulin, D. L. Hawksworth, K. Marhold, D. H. Nicolson, J. Prado, P. C. Silva, J. E. Skog, J. H. Wiersema, and N. J. Turland. 2006. International code of botanical nomenclature (Vienna Code). Regnum Vegetabile 146. Ruggell: A. R. G. Gantner Verlag. Mickel, J. T. and L. Atehortúa. 1980. Subdivision of the genus Elaphoglossum. American Fern Journal 70: 47–68. Moran, R. C. 1991. Monograph of the neotropical fern genus Stigmatopteris. Annals of the Missouri Botanical Garden 78: 857–914. Moran, R. C., J. Prado, and P. H. Labiak. 2009a. Megalastrum (Dryopteridaceae) in Brazil, Paraguay, and Uruguay. American Fern Journal 99: 1–44. Moran, R. C., J. Prado, and P. H. Labiak. 2009b. Megalastrum (Dryopteridaceae) in the West Indies. Brittonia 61: 273–292. Röpert, D. (ed.). 2000- (continuously updated): Digital specimen images at the Herbarium Berolinense. - Published on the Internet http://ww2. bgbm.org/herbarium/default.cfm [accessed 12 Feb 2009]. Rouhan, G., J.-Y. Dubuisson, F. Rakotondrainibe, T. J. Motley, J. T. Mickel, J.-N. Labat, and R. C. Moran. 2004. Molecular phylogeny of the fern genus Elaphoglossum (Elaphoglossaceae) based on chloroplast noncoding DNA sequences: contributions of species from the Indian Ocean area. Molecular Phylogenetics and Evolution 33: 745–763. Smith, A. R. and R. C. Moran. 1987. New combinations in Megalastrum (Dryopteridaceae). American Fern Journal 77: 124–130. Stafleu, F. A. and R. S. Cowan. 1976. Taxonomic Literature, a selective guide to botanical publications and collections with dates, commentaries and types. Vol. I, A–G. 2nd ed. Utrecht: Bohn, Schletema & Holkem. Tardieu-Blot, M.-L. 1954. Sur les Fougères récoltées par Aubert de la Rüe aux îles Kerguelen et Amsterdam. Mémoires de l’Institut Scientifique de Madagascar. Série B. Biologie Végetale 5: 59–64. Tryon, A. F. 1966. Origin of the fern flora of Tristan da Cunha. British Fern Gazette 9: 269–276. Tryon, A. F. and B. Lugardon. 1990. Spores of the Pteridophyta. New York: Springer-Verlag. Vasco, A., R. C. Moran, and G. Rouhan. 2009. Circumscription and phylogeny of the Elaphoglossum ciliatum group (E. sect. Lepidoglossa, Dryopteridaceae) based on cpDNA sequences. Taxon 58: 825–834. Wace, N. M. 1960. Botany of the southern oceanic islands. Proceedings of the Royal Society of London. Series B. Biological Sciences 152: 475–489. Wace, N. M. 1961. The vegetation of Gough Island. Ecological Monographs 31: 337–367. 2010] SUNDUE ET AL.: MEGALASTRUM IN CIRCUMAUSTRAL REGION Wace, N. M. and J. H. Dickson. 1965. The terrestrial botany of the Tristan da Cunha islands In Report of the Royal Society Expedition to Tristan da Cunha, 1962. Philosophical Transactions of the Royal Society of London. Series B, 249: 273–360. Wace, N. M. and M. W. Holdgate. 1958. The vegetation of Tristan da Cunha. Journal of Ecology 46: 593–620. Williams, R. L. 2003. French botany in the enlightenment: the ill-fated voyages of La Pérouse and his rescuers. Boston: Kluwer Academic Publishers. Appendix 1. Synopsis of distributions. South America, Chile/Argentina: M. spectabile. South Pacific Oceanic Islands, Masatierra: M. inaequalifolium, Masafuera: M. glabrius, M. masafuerae. South Atlantic Oceanic Islands, Tristan da Cunha: M. aquilinum, Gough Island: M. aquilinum, M. peregrinum, Inaccessible Island: M. aquilinum, Nightingale Island: M. aquilinum. South Indian Ocean Islands, Île Amsterdam: M. taafense, Île St. Paul: M. taafense. Appendix 2. Index to Collections. The numbers in parentheses refer to the corresponding species. Specimens are listed in alphabetical order by first collector. Collection 475 numbers in bold type indicate type specimens. Megalastrum aquilinum (1), Megalastrum glabrius (2), Megalastrum inaequalifolium (3), Megalastrum masafuerae (4), Megalastrum peregrinum (5), Megalastrum spectabile (6), Megalastrum taafense (7). Aubert s. n. (7). Bertero 1550 (3); 1660 (3). Bridges, T. 806 (6). Cabrera, A. L. 5037 (6). Castellanos 114252 (6). L. A. von Chamisso s. n. (6). Christophersen, E. 23, 423, 1061, 1093, 2217, 2232, 2545 (1). Claude-Joseph 884, 885, 2660, 3046, 5853 (6). Cooper, J. G89053 (5). Cour s. n. (7). de la Sota, R.E 2799, 6011, 6028 (6). du Petit-Thouars, L.-M. A. A. s. n. (1). Dyer, R. A. 3554 (1). Files P., C. 574 (6). GaudichaudBaupre, C. 34 (6). Gunckel, H. 2467 (6). Gunther, E. 13 (6). Hänel, C. CH 021 (5). Hollermayer, P. A. 693, 1933, 156c (6). Hunnewell, F. W. 15852 (6). Jolinon, J.-C. 891, 892, 933, 938, 1016, 1068, 1071, 1101 (7). Junge, E. 2924, 84 (107) (6). Keytel, P. 4713 (1). Krause s. n. (6). Lechler, W. 501 (6). L’Isle, M. G. 3, 28 (7). Looser, G. 5062 (6). Lourteig, A. 78, 50 (7). Mac Gillivray, J. 327 (1). Marticorena, C. 9011, 9026, 9037, 9082, 9153 (3). Mejland, Y. 1575 (1). Meyer, F. G. 9499, 9661 (3). Miller 119 (3). Morisson, J. L. 17326 (3). Noël, P. 29 (7). Poeppig, E. 45 (6). Ricci, M. 402 (3). Roux, J. P. 716 (5); 2092, 2147, 2193 (1). Savatier, L. 272 (6). Schwabe, G. H. 6 (6). Shannon, R. C. 31 (6). Skottsberg, C 12, 65, 168, 274, 275, 339 (3); 466 (2); 448 (4); 721, 730 (3); 731 (2); 921 (6); 1151, 731 bis (3). Sobel, G. 2738 (6). Solbrig, O. T. 3676 (4). Solomon, J. 4559 (6). Sparre, B. 75 (3); 2131, 2948 (6). Stuessy, T. F. 5014, 11644, 11963, 12055, 12129, 15396 (3). Wace, N. M. 12 (1); 133 (5). Wall, E. 9, 3240 (6). Collector unknown s. n. (6).