zyxwvutsrqp zyxwvuts zyx zyxwvu The Aeollanthus buchnerianus group (Labiatae) Olof Ryding Ryding, 0. 1981. The Aeollanthus buchnerianus group (Labiatae). - Nord. J. Bot. 1: 154-164. Copenhagen. ISSN 0107-055X. The Aeollanthus buchnerianus group, i.e., the species of Aeollanthus with an explosive pollination mechanism, is revised. A . canescens Gurke. A . njassae Gurke and A. nyikensis Bak. are reduced to synonyms of A . buchnerianus Briq. A . cuneifolius Bak., A . nodosus Hiern and A . welwitschii Briq. are reduced to synonyms of A . candelabrum Briq. A . cucullatus Ryding, A . neglectus (Dinter) Launert, A . rivularis Hiern, A . sedoides Hiern and A . tuberosus Hiern are maintained. Typification, notes on distribution and habitat, maps and keys are provided for all taxa, descriptions for most species. 0. Ryding, lnst. of Systematic Botany, Vniv. of Uppsala, P.O. Box 541, S-751 21 Uppsala, Sweden. Introduction An explosive pollination mechanism was described in Aeollanthus buchnerianus Briq. (as A . njussae Gurke) from Malawi by Hedge (1972). The same kind of floral structure as in A . buchnerianus is also present in six other species, of which five occur in the highlands of western Angola, some with extensions to other parts of Africa and one only in West Africa. A revision of the species of the A . buchneriunus group, is given here. Material and methods This study is mainly based on material from the following herbaria: BM, BR, C, COI, EA, HBG, K, LD, LISC, LISJC, LISU, M, NBG, P, S, SRGH, UPS, W, Z (abbreviations according to Holmgren and Keuken 1974). N o material has been seen from B and G, but lists of the material present in these herbaria have been obtained. All measurements were made on dry material. Chromosome counts were made on root tip squashes from material cultivated in greenhouses at Uppsala Botanical Garden. The method used is the one described by Hedberg (1970). The lists of collections of A. buchnerianus, A . candelabrum and A . neglectus are not given in extension Taxonomic position and delimitation The A . buchneriunus group differs from the rest of the genus in the structure of the lower lip of the corolla which enables the explosive pollination mechanism described by Hedge (1972). This mechanism has actually been observed only in A . buchnerianus, but owing to the similarity in flower structure it most likely occurs in all other species of the group. At an early stage of anthesis the lower lip of the corolla points straight forward restrained under tension in its position by the two lower stamens. The anthers of these are enfolded in an emarginate hood formed by the apex of the lower lip, which is bent and folded upward (Hedge 1972: Fig. lb). When the lip is touched, e.g. by a pollinating insect the stamens are released explosively, giving off a cloud of pollen. At the same time the lip springs downwards and backwards and remains recurved (Fig. 1C). The species of the A . buchnerianus group also differ from the rest of the genus by the presence of the usually zyxwvuts zyxwvutsrqponmlkjihg 0 NORDIC JOURNAL OF BOTANY NORD. J. BOT. I : 154-164, TROP 010 154 here. A list of all the material examined may be obtained from the author. A . cucullatus Ryding (1980), described in detail in a previous paper, is only briefly treated here. zyxwvuts zyxwvutsrq zyxwvutsr zyxwvutsrqp zyxwvutsrqpon zyxwvutsrq very prominent lobes near the base of the lower lip of the corolla (Fig. 1C).At anthesis, the lobes are longer in relation to the lip than they are in the bud. Their function is uncertain, but perhaps their development is connected with the development of the tension mechanism in the lip. The species of the A. buchnerianus group have transversal lines or rows of dots near the throat on the upper lip of the corolla. This kind of marking seems to be unique within the genus. Other species seen have vertical lines or rows of dots instead. In the subdivision of the genus presented by Briquet (1897)A. buchnerianus was placed in sect. Euaeolanthus 5 Heterodonta with 5 distinct teeth on the fruiting calyx, of which the upper tooth is longer than the others. A. candelabrum Briq. and A. canescens Giirke (here treated as a synonym of A. buchnerianus) were placed in sect. Euaeolanthus 9 Truncata with a truncate or slightly toothed fruiting calyx. In the subdivision of the genus presented by Baker (1900),A. buchnerianus, A. rivularis Hiern and A. candelabrum were placed in his sect. Cryptanthi which is characterized by large bracts. A. sedoides Hiern, A. tuberosus Hiern, A. nodosus Hiern and A. welwitschii Briq. (the last two are ambigous and treated as synonyms of A. candelabrum in the present treatment) were placed in the sect. Phanerunthi with minute bracts. Within the A. buchnerianus group there is, however, a fairly continuous variation both in the dentation of the fruiting calyces and in the size of the bracts. Considering this and the great similarties in the floral structure as a whole, all species of the A. buchnerianus group are undoubtedly of the same origin. The A. buchnerianus group is probably most closely related to some of the other species which have alternately 1 or 2 flowers at each node in the spikes. A. rehmannii Gurke and A. glandulosus Giirke are particularly similar. Like the species of the buchnerianusgroup, they have a subequally 4-lobed upper lip of the corolla with the two side-lobes pointing side-wards, and the anthers on the lower stamens are distinctly larger than those on the upper stamens. Based on the shape of the fruiting calyx, the A. buchnerianus group is here divided into two subgroups: A. buchnerianus, A. sedoides, A . tuberosus and A. rivularis comprise the first subgroup. In these species the upper lip of the fruiting calyx is as long as the lower lip and not folded in the fruiting stage. The basal part is either flattend and truncate or rather high and cupular and has no or only a shallow depression at the insertion of the pedicel (Figs lB, 4F). 1 mm,G RI. zyxwvutsrqp Fig. 1. A. buchnenanus - A: Habit, form from Malawi. - B: Fruiting calyx - C-E: Flowers - F: Somatic metaphase plate B-C: Iwarsson and Ryding 774A (UPS) from Mt Mlanje, Malawi; D: Maguire 921 (NBG) from Potgieterus, Transvaal, South Africa; E: Bruce 86 (K) from Witbank, Transvaal, South Africa. F lwarsson and Ryding 993 1 I* Nord. J . Bot. l(2) 1981 5 pm. F 155 zyxwvutsr zyxw zyxwvutsr zyxwvu zyxwvut zyxwvutsrq A . cucullatus, A . candelabrum and A . neglectus (Dinter) Launert form the second subgroup, which is probably the most specialized of the two. In these species the upper lip of the calyx is longer than the lower lip and folded over it in the fruiting stage. The basal part of the calyx is also higher than in the first subgroup, f truncate and usually with a deep depression at the insertion of the pedicel (Figs 4B, C ) . Usually the second internode of the spikes elongates in the fruiting stage (Figs 5 C , D). A. cucullatus, however, sometimes resembles the species of the first subgroup by the fruiting calyx having a somewhat cupular base and by having equally short nodes in the spikes. Although the A. buchnerianus group is fairly distinct within the genus, it has not been given any taxonomic status in the present account. The remaining part of the genus is very variable and thus a formal subdivision should await a revision of the whole genus. Key to the species of the A. buchnerianus group 1. Leaves sessile, cuneate at the base. Decumbent perennials ................................... 2 1. Leaves petiolate or attenuate into a petiole-like base. Decumbent to erect annuals or perennials 4 2. Fruiting calyx over 3 mm long, with the lobes of the upper lip folded over the lower lip and with a truncate or over 0.55 high basal part 5 . A. cucullatus 2 . Fruiting calyx up to 3 mm long, with the upper lip not folded over the lower lip and a deeply cupular or less than 0.4 mm high fruiting calyx . . . . . . . . . . 3 3. Stem pubescent with both glandular and eglandular hairs .......................... 2. A. sedoides 3. Stem only with glandular hairs . . 3. A . tuberosus 4. Basal part of the fruiting calyx deeply cupular. Leaf base long attenuate. Annual ...... 4. A. rivularis 4. Basal part of the fruiting calyx truncate or almost so. Leaves distinctly petiolate. Annuals or perennials .......................................... 5 5. Upper lip of the calyx about as long as the lower lip, not folded over it in the fruiting stage. At least some hairs on the bracts more than 0.1 mm long ........................... 1. A. buchnerianus 5 . Upper lip of the calyx longer than the lower lip and folded over it in the fruiting stage. All hairs on the bracts less than 0.1 mm ..................... 6 6. Annual herb. Corolla-tube 2.5-4 mm long ............................... 7.A . neglectus 6. Perennial subshrub. Corolla-tube 5.5-7 mm long ........................... 6. A. candelabrum Buchanan 529, Malawi, Shire highlands, 1891 (B syntype t, K lectotype, selected here). A. canescens Giirke 1895b: 147; Cooke 1912: 294; Goosens 1933: 294; Launert and Schreiber 1969: 8. - Orig. coll.: Bolus 1345, South Africa, Graaf Reinet, Mt. Cave, IV. 1890 (B syntype t, K lectotype, selected here, BM, LD, NBG, P, UPS, W). A. nyikensis Baker 1898: 160; Baker 1900: 392. - Orig. coll.: Whyte 119, Malawi, Nyika Plateau, VII. 1896 (K holotype). Pleotrunthus volkmannue Dinter 1928: 124. - Orig. coll.: Dinter 5514, Namibia, farm Auros, 1. 11. 1925 (B holotype t, NBG lectotype, selected here). P. rupicolu Dinter ex Goosens 1933: 252, nom. nud. - Orig. coll.: Dinter 5514 (NBG). Perennial subshrub or sometimes annual herb with an aromatic fragrance, 0.2-1 m high, sometimes with f tuberous roots. Stem ascending or erect, with few to many branches, k fleshy, sometimes thickened at the base or at the nodes, at least in the upper part glandular and usually pubescent. Leaves opposite, somewhat fleshy, petiolate, up to 20-90 x 8-50 mm, ovate to elliptic, obtuse or acute at the apex, subcordate, truncate or attenuate at the case and always with an at- A C D zyxwvu F 2 1. A. buchnerianus Briq. Briquet 1894: 187; Baker 1900: 392. - Orig. coll.: Biichner 571, Angola, Malanje, Bango, IV. 1881 (B holotype t, K lectotype, selected here). A. njussae Giirke 1895a: 346; Baker 1900: 393; Brenan 1954: 44; Hedge 1972: 45, Fig. 1; Gilli 1973: 34. - Orig. coll.: 156 4 6 i Fig. 2. Histogram illustrating the length of the corolla-tubes in mm of - A: A. candelabrum. - B: A . neglectus - C-G: A. buchnerianus from - C: Angola and Namibia. - D: Lesotho and South Africa excluding Transvaal. - E: Transvaal. - F: Zimbabwe. - G: Malawi, Mozambique, Tanzania and Zambia. Each value used represents the mean of measurements of at least 2 flowers in each collection. Nord. J. BOI. l(2) 1981 zy zyxwvutsrqpo 1zyxwvu - zyxwvutsrqp 1 mm,C, F E 1 mm, n.E zyxwvutsrqp zyxwvutsrqpon Fig. 3. A-C: A. tuberosus. - A: Habit. - B: Fruiting calyx. - C: Flower. - D-F: A. rivularis. - D: Part of the specimen. - E: Fruiting calyx, - F: Flower. A: Welwitsch 5595 (COI); B-C: Welwitsch 1628 (BM); D-F: Gossweiler 11225 (COI). + zyxwvu tenuate part near the petiole, glandular with stalked and sessile glands, +_ pubescent with at least 0.1 mm long often greyish hairs; margin crenate or dentate, k undulate; midvein and lateral veins prominent beneath. Inflorescence composed of dense spikes forming a lax panicle; spikes up to 30 (60) mm long; the spike on the main axis usually with 2 flowers at each node; other spikes one-sided with alternately 1 or 2 flowers at each node and with sterile bracts on the back; internodes up to 3 mm long in the fruiting stage; bracts ovate to lanceolate, acuminate to acute at the apex, 2-6.5 X 1-5 mm, often purple, k glandular, pubescent or ciliate; sterile bracts somewhat smaller, obtuse or acute at the apex. Fruiting calyx circumscissile at the base, 1.7-3.8 Nord J . Bot. l(2) 1981 mm long, glandular and papillose to pubescent; upper lip 3-lobed, about as long as and not folded over the lower lip; lower lip 2-lobed; basal part circular, truncate or slightly cupular, with a shallow depression at the insertion of the pedicel, 0.8-1.4 mm in diam., 0.2-0.45 mm high. Corolla pale violet, pink or white, glandular and papillose to pubescent on the outside; tube 3.5-8 mm long; upper lip subequally 4-lobed, with violet markings near the throat; lower lip with a hood at the apex and with 2 f prominent lobes near the base. The 2 upper stamens longer than the lower, with ca. 0.5 long anthers; the 2 lower with 0.5-0.8 mm long anthers. Style bifid. Nutlets smooth or almost so, black, 0.65-1.05 x 0.5-0.85mm. 157 zyxwvutsrq zyxwvutsr zyxwv zyxw zyxwvutsrqp Distribution and habitat. The highlands of Angola, Namibia and Zambia and also from southern Tanzania southwards to eastern South Africa and Lesotho (Fig. 6A). According to Compton (1966) this species (referred to as A. canescens) also occurs in Swaziland. The collections from Swaziland, determined as A. canescens in NBG (Compton 25547,30578,31215, 30420, Karsten s.n.) however all belong to A. rehmannii. The species grows on rocks or shallow soil, usually in shaded or humid places; alt. 900-2600 m. more than 0.1 mm long hairs on the bracts. One very aberrant collection is Miller 3568 (SRGH) which has a short and very robust stem and ca. 60 mm long spikes. It is from Besna Kobila in Zimbabwe. Some of the material from northern Transvaal has deeply crenate leaves. The most divergent form, for which the name A. canescens has been used, occurs in South Africa with the exception of northern Transvaal. In this form most parts of the plant are smaller than in preceding forms, especially the corolla, which has a rectangular base, instead of a clearly lobed base of the lower lip (Fig. 1E). The pubescence is more greyish with shorter hairs. It is usually a perennial with a thickened base, but apparently annual plants also occur. From Zimbabwe to Natal and the O.F.S. in South Africa, there is a complete gradation between the “njassae-form” and the “canescens-form”. In its short corolla tube the “canescens”-form diverges conspicuously from the other forms, as shown in Fig. 2. A. buchnerianus has often been confused with A. elsholzioides Briq., which is endemic on the Huilla plateau in Angola. The great similarity between the two species is only superficial. A. elsholzioides deviates from A. buchnerianus especially in the floral structure. It has neither a hood nor lobes on the lower lip of the corolla. Variation and affinities. A. buchnerianus is probably most closely allied to A. sedoides, A. tuberosus and A. rivularis. It is easily distinguished from these species by the clearly petiolate leaves and usually also by a flatter and more truncate basal part of the fruiting calyx. The wide variation present in A. buchnerianus is largely geographically correlated, and will here be briefly described area by area. According to Briquet (1894) the type of A. buchnerianus was collected in Zaire, but according to MendonGa (1962) Max Buchner was visiting Malanje in Angola at the time when the plant was collected, and the correct locality is probably the Bango ca. 140 km E of Malanje. The type collection consists only of an inflorescence and a few loose leaves, but resembles the forms which occur at altitudes below 2000 m the in Benguela Division in Angola. These are Chromosome number. 2n = 34 was reported for A. pubescent all over and like other forms, which occur bucherianus (as A. njassae) from Mt. Malanje in Malawi below 2000 m in Angola and Namibia, they usually by Hedge (1972) and (as A. canescens) from South Afhave tuberous roots. rica by Ratter (1973). This number was also counted in The material from altitudes below 2000 m in the Iwarsson and Ryding 993 (UPS),collected on ChimalHuilla Division in Angola has conspicuously narrow iro hills in Malawi (Fig. 1F). The same number has also bracts, while material from altitudes above 2000 m in been counted in several other species of the genus Benguela and Huilla consists of very robust specimens (Ryding unpubl.). with long pubescence resembling the type ofA. nyikensis (see below). The type of A. nyikensis was collected in northern Selected collections, Angola: Benguela Div., Bailendo-Luimbale, Mountain of Moco, 3. VI. 1940, Gossweiler 12276 (BM, Malawi and represents a form that also occurs in south- LISC); Chiango, 5. 111. 1962, Texeira and Andrade 6530 western Tanzania and north-eastem Zambia. It usually (COI, LISC). Huilla Div., Sa da Bandeira, 23. 111. 1962, Hengrows in fairly unshaded places and, especially in those riques 309 (K, LISC, SRGH). Lesotho: Leribe, I. 1913, sites, has robust stems and very short internodes. It also Dieterlen 36 (K, NBG, P, UPS). Malawi: Nchisi Mt., 10. VII. 1978, Iwarsson and Ryding 919 (K, MAL, UPS). Mozamdisplays dense pubescence of long hairs and often has bique: Manica and Sofala, Chimanimani Mt., 8. VI. 1967, narrow leaves with an attenuate base and only a short Grosvenor 355 (K, LISC, SRGH). Namibia: Otjivarongo D., Great Waterberg, 3. IV. 1968, Kers 2973 (M, S). South Africa: petiole . The syntypes ofA. njassae were collected in southern Transvaal, Johannesburg, 8. IV. 1945, Wasserfall 905 (BM, BR, LD, S, UPS); Pietersburg D., Blouberg, 29. IV. 1954, Malawi. They represent an only slightly pubescent form Codd 8154 (K, UPS). Tanzania: Songea D., Matagoro hills, with thinner branches which usually grows in shaded 14. VI. 1956, Milne-Redhead and Taylor 10815 (B, BR, EA, situations. Material from south-eastern Tanzania, Cen- K); Stromgebiet des oberen Ruhudje, Schlieben 800 (BM, BR, tral Region of Malawi, Mozambique and eastern Zim- G, K, M, P, S). Zambia: Mwinilunga D., Kalene hill, 23. 11. 1975, Hooper and Townsend 347 (C, K, SRGH). Zimbabwe: babwe is more or less intermediate between the type of Salisbury, IV. 1920, Eyles 2175 (K, NBG, SRGH). A. njassae and the type of A. nyikensis. Much of the material from Zimbabwe consists of more or less annual and herbaceous, only slightly pubescent collections which often have dentate leaves. 2. A. sedoides Hiern occurs in Hiern 1900: 870; Baker 1900: 395. - Orig,: Welwitsch 1629, They thus A’ neglectus, which Zimbabwe, but can be distinguished from this species by Angola, Cuanza Norte, Pungo Andongo, Pedra Cabondo, IV, the unfolded upper lip of the fruiting calyx and by the 1857 (BM lectotype, selected here), zy 158 Nord. J . Bot. l(2) 1981 D z B zyxwv zyxwv zyxwv i m m . 0, C, F, -zyxwvutsr I em. A, I, zyxwvutsrqpon zy zyxwvutsrqpon 1 mm. D. a, Fig. 4. A-D: A. neglectus. - A: Habit. - B: Fruiting calyx. - C: Basal part of the fruiting calyx with the pedicel. - D: Flower. E-G: A. sedoides. - E: Habit. - F: Fruiting calyx. - G: Flower. B-D: Wild 4807 (K); F-G: Henriques 887 (LISC). Nord. J. Rot. l(2) 1981 159 zyxwvu zyxwvutsrqp zyxwvutsr zyxwvutsrq Perennial, prostrate or decumbent herb. Stem fleshy, rooting at the nodes, sparsely hirsute all over, glandular and pubescent with softer hairs on the upper part. Leaves opposite or sometimes ternate, on the shortshoots fasciculate, fleshy, sessile, elliptic, up to 10-20 X 3-10 mm acute at the apex, cuneate at the base, hirsute, and usually with both stalked and sessile glands; margin minutely crenate; veins obscure beneath. Inflorescence composed of spikes forming a lax panicle; the spike on the main axis usually with opposite flowers, other spikes one-sided, with alternately 1 or 2 flowers at each node, with sterile bracts on the back; internodes equal in length or almost so; bracts elliptic to linear, 2-4 X 0.8-1.5 mm, glandular and pubescent. Fruiting calyx circumscissile at the base, 2-3 mm long, pubescent and glandular; upper lip 3-lobed, about as long as and not folded over the lower lip; lower lip 2-lobed; basal part circular, k cupular, 1.0-1.3 mm in diam., 0.2-0.5 mm high. Corolla pale violet, glandular and pubescent on the outside, tube 4.5-6 mm long; upper lip subequally 4-lobed with violet markings near the throat; lower lip hooded at the apex, with 2 acuminate lobes near the base and with a 2 mm long narrow basal part. The 2 upper stamens longer than the lower, with ca. 0.4 mm long anthers; the 2 lower with ca. 0.9 mm long anthers. Style bifid, much longer than the corolla. Nutlets smooth, black, 0.8-1.0 x 0.7-0.9 mm. 3. A. tuberosus Hiern Hiern 1900: 870, non Gurke; Baker 1900: 394. - Orig. coll.: Welwitsch 1628, Angola, Cuanza Norte, Pungo Andongo, Mutillo by Pedras de Guinga, 111. 1857 (BM lectotype, selected here). Decumbent herb. Stem with stalked glands at least on the upper part. Leaves fleshy, sessile, elliptic, up to 28 x 4 mm, acute at the apex, cuneate at the base, papillose and with stalked glands; margin minutely crenate; veins obscure beneath. Inflorescence composed of spikes forming a lax panicle; spikes (perhaps with the exception of the one on the main axis) one-sided with alternately 1 or 2 flowers at each node, with sterile bracts on the back; bracts elliptic, ca. 3 X 1 mm, glandular; sterile bracts smaller. Fruiting calyx circumscissile at the base, 2.5-3 mm long, glandular; upper lip 3-lobed, about as long as and not folded over the lower lip; lower lip 2-lobed; basal part deeply cupular, ca. 1.6 mm in diam., ca. 0.4 mm high, Corolla pale violet, glandular on the outside; tube 6-7 mm long; upper lip subequally 4-lobed; lower lip hooded at the apex, with 2 acuminate lobes near the base and with a ca. 2 mm long narrow basal part. The 2 upper stamens longer than the lower, with ca. 0.6 mm long anthers; the 2 lower with ca. 0.8 mm long anthers. Style bifid. Nutlets not known. Distribution and habitat. Only known from Pungo Andongo in Angola (Fig. 6C). The species grows on rocks. Distribution and habitat. Endemic to the highlands of western Angola (Fig. 6C). The species grows on rocks or shallow soil; alt. 1300-2500 m. Variation and affinities. The few collections of A. sedoides show little variation. The species is undoubtedly most closely related to A. tuberosus and A . rivularis (see under those species). At least superficially A. sedoides is also very similar to A. cucullaaus in the second subgroup (see under Taxonomic position and delimitation). Both these species have a decumbent habit and sessile elliptic leaves, but A. sedoides can be distinguished from A. cucullatus by its fruiting calyx being less than 3 mm long, with an upper lip which is not folded over the lower lip and a deeply cupular or less than 0.35 mm high basal persistent part, and also by a basal, more than 1.5 mm long, narrow part of the lower lip of the corolla. The pubescence of the stem is more rigid, and the bracts are narrower, their length being at least twice their width. Affinities. A . tuberosus is most similar to A. sedoides, but differs from this species by the absence of eglandular hairs on the stem, the elongated alternate node of the spikes in the fruiting stage, the somewhat wider basal part of the fruiting calyx and the somewhat broader bracts. According to Hiern (1900) it also has a tuberous root and an aromatic fragrance. Further collections may show, however, that these differential characters are not consistent. zyxwvutsr Collection in addition to the type. Angola: Cuanza Norte, Pungo Andongo, Pedras de Guinga, 111. 1857, Welwitsch 5595 (C, COI, K). 4. A. rivularis Hiern Hiern 1900: 869; Baker 1900: 391. - Orig.: Welwitsch 1630, Angola, Cuanza Norte, Pungo Andongo, by the stream of the Presidium, 11. 1857 (BM lectotype, selected here). zyxwvutsrq zyxwvuts Collections in addition 10 the fype. Angola: Benguela Div., Moco Montain, 22.11. 1938, Gossweiler 11988 (COI); 3 . VI. 1946, Gossweiler 12245 (LISC); Alto Huama, Sumbo hill, 31. 111. 1966, Henriaues 887 CK. LISC. SRGH). Cuanza Sul Div.. Santa Comb-Am'boiva, 28: 111. 1973, Barnpi and Martins 4297 (BR, K, LISC); 10. 111. 1965, dos Santos 1422 (COI, LISC). Cuanza Norte Div., Pungo Andongo, IV. 1857, Welwitsch 5594 (BM, K, P). 160 Annual herb. Stem decumbent up to 0.6 m high, with few to many branches, glandular. Leaves opposite, somewhat fleshy, elliptic to obovate, up to 17-30 x 7-12 mm, acute to obtuse at the apex, with a long attenuate base, with stalked and sessile glands, papillose; margin crenate towards the apex. Inflorescence composed of spikes forming a lax panicle; spikes one-sided with alternately 1 or 2 flowers at each node; bracts el- Nord. J. Bot. l(2) 1981 zyxw liptical, 2 4 X 0.7-1.2 mm,acute at the apex, glandular and papillose. Fruiting calyx circumscissile at the base, 2-3 m m long, glandular and papillose; lips truncate, equal in length and unfolded; basal part circular, deeply cupular, 1.0-1.3 mm in diam., ca. 0.5 m m high. Corolla pale violet, glandular and papillose on the outside; tube 3-4 m m long; upper lip subequally 4-lobed with violet markings near the throat; lower lip with a hood at the apex and 2 acuminate lobes near the base. The 2 upper stamens longer than the lower with ca. 0.5 m m long anthers; the 2 lower with ca. 0.8 mm long anthers Style bifid. Nutlets smooth, black, ca. 0.9 X 0.7 mm. Distribution and habitat. Cuanza Norte and Malanje Divisions in Angola (Fig. 6D). The species grows on rocks o r shallow soil; alt. 1000-1100 m. Variation and affinities. The few collections of A. rivularis show little variation. The species is most similar to A. sedoides and A . tuberosus. All these species have an unfolded upper lip of the fruiting calyx, and a cupular basal part. A. rivularis is easily distinguished from both the two latter species by its annual habit, the attenuate leaf base and the shorter corolla-tube. According to Hiern (1900) it also differs from A. tuberosus by being scentless. zyxwv Collections in addition to the type. Angola: Cuanza Norte Div. Pungo Andongo, by the stream of the Presidium, 11. 1859, Welwitsch 5591 (C, COI, P). Malanje Div., Lucala falls, 18. IV. 1922, Dawe 398 (K); Dugue de Braganza, 28. 111. 1937, Exell and MendonGa 95 (COI); Rianzondo, 111. 1937, Gossweiler 11825 (COI). 5. A. cucullatus Ryding Ryding 1980: 235, Fig. 1. - Orig. coll.: Jacques-Felix 8461, Cameroun, Poli near Vokre, 3. X. 1967 (P holotype). A . repens sensu Morton 1962: 241; 1963: 457, quoad specim. Hepper 1356. Distribution and habitat. The highlands of Cameroun and Nigeria (Fig. 6C). The species grows on rocks or shallow soil; ah. 1200-2000 m. Additional collections. Cameroun: Nganha Mts., Ca. 60 km E of N'Gaoundere, 3. XII. 1964, W. de Wilde 4507 (BR); Djuttitsa, 12. XI. 1966, Meurillon 507 (BR). zyxwvutsrqpo zyxwvutsrqpon 6. A. candelabrum Briq. zyxwvutsrqpon zyxwvutsrqp lmms c Fig. 5 . A . candelabrum. - A-C: form from the Huilla Plateau in Angola. - A: Habit. - B: Flower - C: A part of a spike with fruiting calyces. - D: A semidiagramatic drawing of the upper part of an inflorescence from a specimen with opposite leaves showing the arrangement of the flowers. - E: A leaf of the form in Cuanza Norte. - B-C: Barbosa and Correira 8946 (UPS). E: Welwitsch 5596 (COI). Nord. I. Bot. l ( 2 ) I Y X l Briquet 1894: 186; Baker 1900: 292. - Orig. coll.: Mechow 146, Pungo Andongo, 1879 (B holotype t, Z lectotype, selected here). A . welwitschii Briquet 1894: 188; Hiern 1900: 868; Baker 1900: 293. - Orig. coll.: Welwitsch 5482, Angola, Huilla plateau, V. 1860 (G holotype, not seen, BM, K, LISU, P). A. nodosus Hiern 1900: 868; Baker 1900: 395. - Orig. coll.: Welwitsch 1627, Angola, Cuanza Norte, Pungo Andongo, near Cabondo, IV. 1857 (BM lectotype, selected here, LISU). A. cuneijolius Baker 1900: 232. - Orig. coll.: Welwitsch 5480, Angola, Huilla Prov., V. 1860 (BM holotype, COI, K, LISU, P). 161 zyxwvutsrq zyxwvutsrq zyxw zyxwvutsr zyxwvutsrq zyxwvuts zyxw *= Fig. 6. Known distribution of - A: A. buchnerianus, 0 = inexact locality. - €3: A. candelabrum, 0= inexact locality. - C: 0 = A. cucullatus, A. sedoides, 0 = A. tuberosus. - D: 0 = A . neglectus, f = A. rivularis. 162 Nord. J. Bot. I(2) 1981 zyxwvutsrq zyx Subshrub, up to 1 m high, with an aromatic fragrance. easily distinguished from A. cucullutus by the petiolate Branches sometimes thickend at the nodes. Leaves ter- leaves and the usually more erect growth. nate or opposite, somewhat fleshy, petiolate, ovate or elliptic, 35-95 X 12-35 mm, obtuse or acute at the Selected collections, Angola: Benguela Div., Caconda, 111. 1878, Anchieta 167 (LISU) Country of Ganguellas and Amapex, attenuate at the base, sometimes purple, densely buellas, 1910, Gossweiler s.n. (K). Bie Div., Menongue, Cuchi, glandular with both stalked and sessile glands and up to 3. IV. 1960, Mendes 3417 (LISC). Cuanza Norte Div., Pungo 0.1 mm long eglandular hairs; margin minutely to dis- Andongo, 31. 111. 1937, Exell and MendonGa 187 (BM, COI, tinctly crenate, undulate; midvein and lateral veins LISJC). Cuanza Sul Div., Capir, 16. 111. 1933, Gossweiler (COI, K, LISJC); near Cela, 10. 111. 1965, dos Santos prominent beneath. Inflorescence composed of lax 9844 1419 (COI); near St. Comba, 10. 111. 1965, dos Santos 1420 spikes forming a lax panicle, with 3 or 2 branchlets on (LISC); Gabela, 16. 111. 1967, Texeira et al. 10205 (LISC). the nodes of the main axis; the spike on the main axis Malange Div., Rianzondo, 111. 1937, Gossweiler 11829 (COI). with whorls of 3 flowers or opposite flowers; other Huilla Div., Omupovi, 1. IV.1960, Barbosa and Correira 8946 SRGH, UPS); Humpata, V. 1903, Fritsche 86 (S); spikes one-sided with alternately 1 or 2 flowers at each (LISC, Sada Bandeira, 17. IV. 1960, Mendes 3644 (LISC); Lagoa node, with sterile bracts on the back; the internodes Ivantala, 1 . 11. 1956, Torre 8623 (LISC); Huilla, 10 km from above the 2-flowered nodes elongating in the fruiting the mission, 6. 11. 1956, Torre 8662 (LISC). stage, 3-10 mm long; bracts ovate or elliptic, 2-4 X 1.0-1.8 mm, acute at the apex, often purple, densely glandular, and pubescent or ciliate with very short, eglandular hairs; sterile bracts smaller. Fruiting calyx circumscissile at the base, 2.5-3.5 mm long, eglandular; 7. A. neglectus (Dinter) Launert upper lip longer, folded over the lower lip, truncate or Launert 1957: 310; Launert and Schreiber 1969: 9. - Plec3-lobed; lower lip truncate; basal part circular, truncate, tranthus neglectus Dinter 1926: 380. - Orig. coll.: Dinter 7089, 0.8-1.2 mm in diam., 0.45-0.6 mm high, with a deep Namibia, Karibib D., Klein Ameib, 1. 111. 1934 (M lectotype, hollow at the insertion of the pedicel. Corolla pale vio- BM, G , not seen, HBG, K, Z , not seen). let, glandular, papillose or pubescent on the outside; tube 5.5-7 mm long; upper lip subequally 4-lobed with Annual herb, 10-70 (-150) cm high, with an unpleasant violet markings near the throat; lower lip hooded at the odour. Stem with few to many branches or sometimes apex, with 2 acuminate lobes near the base and with a unbranched, ascending to erect, f tetragonal, densely ca. 2 mm long narrow basal part. The 2 upper stamens glandular and with a very short pubescence. Leaves longer with sterile dwarfed anthers; the 2 lower with opposite, somewhat fleshy, petiolate, ovate, obtuse or 0.8-0.9 mm long anthers. Style bifid. Nutlets smooth, acute at the apex, subcordate, truncate or attenuate at the base, always attenuate near the petiole and with a black, 0.8-0.9 x 0.6-0.7 mm. narrow crenate or dentate, decurrent margin, densely Distribution and habitat. Endemic to the highlands of glandular with stalked glands and sometimes with a few western Angola (Fig. 6B). The species grows on rocks sessile glands, and w i t h j p to 0.1 mm long eglandular hairs; midvein and lateral veins prominent beneath. Inor shallow soil; alt. 1150-2000 m. florescence composed of lax spikes forming a lax panicle, ascending from near the base of the plant; spikes Variation and affinities. Most material of A. candelab- one-sided, with alternately 1 or 2 flowers at each node, rum can be divided into two main form groups, one with with sterile bracts on the back; the internodes above the a northern, and one with a southern area of distribution. 2-flowered node elongating to 5-12 mm in the fruiting The type collections of A. candelabrum and A . stage; bracts ovate, elliptic or obovate, 1-3 X 0.4-1.5 nodosus belong to the first group, which occurs in mm, acute or acuminate at the apex, glandular and Cuanza Norte, Malanje and Cuanza Sul Divisions in shortly pubescent or ciliate; sterile bracts shorter and Angola. It is characterized by an erect, robust stem, narrower. Fruiting calyx bent outwards, circumscissile usually thickend at the nodes, opposite broad leaves at the base, 2-4 mm long, f glandular and papillose; with a short petiole (Fig. 5E), and by truncate lips of the upper lip longer, folded over the lower, with 3 rather long lobes; lower lip truncate; basal part circular, truncalyx. The type collections of A. welwitschii and A . cate, 0.9-1.3 mm in diam., 0.5-0.75 mm high and with cuneifolius belong to the second group, which occurs in a deep hollow at the insertion of the pedicel. Corolla, the highlands near Huilla. It usually has a more decum- violet, pink or white, f glandular and pubescent on the bent growth than the preceding group, ternate, narrow outside; tube 2 . 5 4 mm long; upper lip subequally leaves with a long petiole, 3-lobed upper lip of the calyx 4-lobed with markings near the throat; lower lip with a and very lax spikes. The material from Bie and Ben- hood at the apex and 2 acuminate lobes near the base. guela Divisions is mostly intermediate between the two The 2 upper stamens longer than the lower, usually with dwarfed and sterile anthers, up to 0.25 mm long; the 2 mentioned form groups. A. candelabrum is closely related to A. neglectus (see lower with 0.45-0.6 mm long anthers. Style bifid. Nutunder this species) and to A. cucullutus. It is, however, lets smooth, black, 0.65-0.9 x 0.55-0.7 mm. zyxw zyx zyxwvutsr zyxwvuts Nord. 1. Bot. l(2) 1981 163 zyxwvutsrq zyxwvu zyxwvu Distribution and habitat. Angola, Namibia, Botswana, Zimbabwe and South Africa (N Transvaal) (Fig. 6D). The species grows on rocks and shallow soil, usually in humid or shaded places; alt. 450-1400 mm. Variation and affinities. A . neglectus is probably the most specialized species of the A. buchneriunus group. It does not vary to any greater extent, but many of the Angolan collections have a more attenuate leaf base, and are in this respect particularly similar to the closely related species A. candelabrum. Both A . candelabrum and A . neglectus have a folded upper lip and a truncate base of the fruiting calyx. All the material of A. neglectus can, however, be distinguished from A. candelabrum by the annual habit, by having a corolla tube up to 4.5 mm long (Figs 2A-B) and by having the same arrangement of the flowers on the spike of the main axis as on the other spikes. References Baker, J. G. 1898.Diagnoses africanae. - Bull. Misc. Inform. 1898: 145-164. - 1900.Aeolanthus. - In: Thieselton-Dyer, W. T. ed., Flora of Tropical Africa, 5: 388-398. Ashford. Brenan, J. P. M. (et al.) 1954.Plants collected by the Vernay Nvasaland exDedition of 1946. - Mem. New York Bot. Gird. 9 (1): i-132. Briauet. J. 1894.Labiatae africanae 1. - Bot. Jahrb. Syst. 19: i6O-194. - 1897. Labiatae. - In: Engler, A. Die natiirlichen Pflanzenfamilien IV 3a: 183-375. Compton, R. H. 1966.An annotated check list of the Flora of Swaziland. Suppl. 4. - Mbabane, Swaziland. Cooke, T. 1912.Aeolanthus. -In: Thieselton-Dyer, W. T.ed., Flora Capensis 5 (Sect. 1): 294-295. London. Dinter, K. 1926.Index der aus Deutsch-siidwestafrica bis zum Jahre 1917 bekannt gewordenen Pflanzenarten 19.- Fed. Repert. Spec. Nov. Regni Veg. 22: 375-383. - 1928. Sukkulentenforschung in Siidwestafrika 2. - Fed. Repert. Spec. Nov. Regni Veg. Beih. 53: 1-145. Gilli, A. 1973.Beitrage zur Flora von Tanganyika und Kenya. IV. Sympetalae (ohne Compositae). - Ann. Naturhistor. Mus. Wien. 77: 15-57. Goosens, A. P. 1933. A note on the floral evolutionary tendencies, differentiation, and distribution of South African Labiatae. - Trans. Roy. SOC. South M i c a 21 (3): 352-363. Giirke, M. 1895a.Aeolanthus. - In: Engler, A., Die Pflanzenwelt Ostafrikas und der Nachbargebiete C: 345-346. - 1895b. Labiatae africanae 3. - Bot. Jahrb. Syst. 22: 128-148. Hedberg, I. 1970.Cytotaxonomical studies on Anthoxanthum odoratum L. s. lat. - Hereditas 64: 153-176. Hedge, I. C. 1972.The pollination mechanism of Aeollanthus njussue. - Notes Roy. Bot. Gard. Edinburgh, 32: 45-48. Hiern, W. P. 1900.Catalogue of the African plants collected by Dr. Friedrich Welwitsch in 1853-61, 1 (4).- London. Holmgren, P. K. and Keuken, W. 1974.Index herbariorum 1. The herbaria of the world, ed. 6.- Regn. Veg. 92. Launert, E. 1957.Neue Arten und Erstfunde aus Siidwestafrica. -Mitt. Bot. Staatssamml. Miinchen, 2 (16): 310. - and Schreiber A. 1969.Lamiaceae. - In: Merxmiiller, H. Prodromus einer Flora von Siidwestafrika 123: 1-31. Miinchen. Mendonca. F. A. 1962.Botanical collectors in Aneola. - In: Fern'andes, A., ed., Comptes Rendus IV' Reuion AETFAT-1961:111-121. Lisboa. Morton, J. K. 1962.Cytotaxonomic studies on the West African Labiatae. - J. Linn. SOC.(Bot.) 58: 231-281. - 1963: Aeolanthus. - In: Hepper, F. N., Flora of West Tropical Africa, 2: 247. London. Ratter, J. A. and Milne, C. 1973. Some angiosperm chromosome numbers. - Notes Roy, Bot. Gard. Edinburgh, 32: 429-435. Ryding, 0.1980.Notes on the Aeollanthus from West Africa (Labiatae). - Bot. Notiser, 133 (2):233-237. zyxwvutsrq Selected collections, Angola: Cuanza Sul Div., Amboim, Capir, 111. 1933, Gossweiler 9837 (COI, LISC). MoGamedes Div., Dois Irmaos, 30. IV. 1960,Mendes 3876 (LISC); near Virei, 21. V. 1962, A. de Menezes 289 (K, LISC, SRGH). Huilla Div., Huilla, Jambos fort, 15. V. 1909, Pearson 2516 (K). Botswana: Tsodilo hills, 2. V. 1975,Biegel et al. 5059 (BR, SRGH). Namibia: Kaokoveld D., Andova, 25. 111. 1974, Merxmiiller and Giess 30555 (K, M); Otjiyanyasemo, 10. IV. 1973, Giess and van der Valt 12690 (K); Ombepera, 10. IV. 1957,de Winter and Leistner 5482 (K, M). Karibib D., farm Ameib, 15. IV. 1968,Wanntorp 960 (S); farm Etemba, 5. IV. 1969, Meyer 10813 (M). Okahandja D., Wilmhelmsberg, 16. IV. 1907, Dinter 573 (NBG); Okahandja, IV. 1912, Dinter 2591 (NBG). Omaruru D.,Okombane Reserve, 8. IV. 1963, Giess, Volk and Bleissner 6275 (M); 12 mls NW of Omaruru, 10. IV. 1968, Kers 3033 (M, S); Erongo Mts, 21. 111. 1965, Tolken and Hardy 151 (K). South Africa: Transvaal, Dongola reserve, 29. IV. 1948,Codd 4126 (K). Zimbabwe: Bulalima Mangwe D., Mt. Jim, 9. IV. 1974, Ngoni 360 (SRGH). Matopo D., Matopos, 16. 111. 1957, Gaeley 144 (SRGH). Mrewa D., Swawanoe river, 23. IV. 1956, Wild 4807 (K, SRGH). Mtoko D., Mt. Mpotipoti, 14. 11. 1962, Wild 5646 (BR,:K, SRGH). Umtali D., Zinunyas reserve, 8. IV. 1956, Chase 6067 (BM, K, SRGH). zyxwvutsrqp zyxwvut Acknowledgements - I am particulary indebted to Dr M. Thulin and Prof. 0.Hedberg for critically reading my manuscript. I also wish to thank the Directors and Curators of BM, BR, C, COI, EA, HBG, K, LD, LISC, LISJC, LISU, M, NBG, P, S. SRGH, UPS, W, Z for placing material at my disposal, and Dr E. van Jaarsveld, Kirstenbosch Bot. Garden, for providing living material of A. buchneriunus from South Africa. 164 Nard. J . Bat. I(2) 1981