A new species of Stephanopodium (Dichapetalaceae) from eastern Brazil PEDRO FIASCHI1 AND ANDRÉ M. AMORIM2,3 1 Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, 321, Cidade Universitária, São Paulo, SP 05508-090, Brazil; e-mail: pedrofiaschi@gmail.com 2 Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz. Rod, Ilhéus-Itabuna km 16, Ilhéus, BA 45662-900, Brazil; e-mail: amorim.uesc@gmail.com 3 Herbário Centro de Pesquisas do Cacau. Rod, Ilhéus-Itabuna km 22, Ilhéus, BA 45650-900, Brazil Abstract. A new species of Stephanopodium (Dichapetalaceae) from tabuleiro forests in southern Bahia is here described and illustrated. This species, named Stephanopodium gracile because of its slender habit, is compared to S. blanchetianum and S. organense. From these two species, S. gracile can be distinguished by the inflorescences on the apical portion of the leaf petiole, young branches with sparse short appressed trichomes, and glabrous leaves; from S. blanchetianum it differs also by leaf blades with an acuminate (vs. usually obtuse or rounded, and sometimes acute) apex. Key Words: Atlantic Forest, Malpighiales, tabuleiro forest, Bahia. Resumo. Uma espécie nova de Stephanopodium (Dichapetalaceae) de florestas de tabuleiro no sul da Bahia é aqui descrita e ilustrada. Esta espécie, nomeada Stephanopodium gracile devido ao hábito esguio, é comparada a S. blanchetianum e S. organense. Dessas duas espécies S. gracile pode ser diferenciada principalmente pelas inflorescências na porção apical do pecíolo, ramos jovens com tricomas adpressos curtos e esparsos e folhas glabras; de S. blanchetianum ela ainda difere pelas lâminas com ápice acuminado (vs. geralmente obtuso ou arredondado, ou às vezes agudo). The neotropical genus Stephanopodium Poepp. & Endl. (Dichapetalaceae) comprises 15 species, the vast majority of which occur in rainforests in northern South America and the Brazilian coast, with the exception only of S. costaricense Prance, from southern Costa Rica (Prance, 1995). The geographic distribution of Stephanopodium is disjunct between these two centers of diversity, as no species of the genus has been recorded so far from both the Amazonian rainforests and the cerrados and seasonally dry forests of the Brazilian Plateau. The two remaining genera of Dichapetalaceae (Dichapetalum Thouars and Tapura Aubl.) are represented by several species in the Amazonian forests, and Tapura is also found in the Atlantic forests of Espírito Santo (Prance, 1997). Stephanopodium can be easily distinguished from Tapura by the flowers with corolla lobes shorter (vs. longer) than the corolla tube and anthers borne on the tube (vs. on slender filaments), but the two genera may be hard to tell apart when flowers are lacking. Stephanopodium differs from Dichapetalum by the connate (vs. free) petals, stamens adnate to (vs. free from) the corolla tube, and the sessile (vs. usually long-pedunculate) inflorescence (Prance, 1972, 2004). There are seven endemic species of Stephanopodium in the Atlantic forests of Brazil, one of which (S. gracile Fiaschi & Amorim) is here described. This new species is illustrated and compared with previously studied similar species (Rizzini, 1952; Prance, 1972, 1995). Information on the geographic distribution, Brittonia, 64(2), 2012, pp. 153–156 © 2011, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A. ISSUED: 1 June 2012 154 BRITTONIA habitat preferences, and phenology of this new species is also presented. Stephanopodium gracile Fiaschi & Amorim, sp. nov. Type: Brazil. Bahia. Prado, km 21 da Rodovia Itamaraju-Prado, 17 Feb 1994 (fl), J. R. Pirani, J. A. Kallunki, I. Cordeiro & P. L. R. Moraes 3002 (holotype: SPF; isotypes: CEPEC, HUEFS, K, MBM, NY, RB). (Fig. 1) Species nova a Stephanopodio blanchetiano inflorescentiis ex parte apicali (non e mediana) petioli orientibus, ramis juvenibus trichomatibus sparsis brevibus adpressis (non trichomatibus densis minutis sessilibus stellaribus) ornatis, foliis glabris (non costa foliorum in facie abaxiali trichomatibus minutis stellaribus ornata), laminis plerumque membranaceis vel subchartaceis (non chartaceis vel subcoriaceis), apicibus acuminatis (non apicibus plerumque obtusis vel rotundatis, interdum acutis) differt. A Stephanopodio organensi inflorescentiis ex parte apicali (non e mediana) petioli orientibus, ramis juvenibus trichomatibus sparsis brevibus adpressis (non trichomatibus et densis minutis sessilibus stellaribus et longis ascendentibus immixtis) ornatis, stipulis trichomatibus sparsis adpressis (non densis setosis) ornatis, foliis glabris (non costa foliorum in facie abaxiali trichomatibus et minutis sparsis stellaribus et longis ascendentibus mixtis ornata) differt. Treelets, 3–4 m tall, young branches glabrescent, with sparse short appressed trichomes, slightly striate longitudinally. Leaf blades slightly obovate, oblanceolate, elliptic, or narrowly elliptic, membranous to subchartaceous, 8.1–13 × 3.7–5.5 cm, with 4–7 rounded glands at the proximal half of the blade, the base cuneate to obtuse, sometimes slightly asymmetric, the margin entire, plane, the apex acuminate, glabrous on both surfaces; venation brochidodromous, the midrib impressed to distally plane above, prominent beneath; primary veins 6–10 pairs, plane above, slightly prominent beneath; petioles 4–8 mm long, plane to slightly canaliculate when sterile or with a slightly raised adnate inflorescence axis when fertile and with dense short appressed trichomes adaxially, with sparser longer trichomes abaxially. Stipules 1.5–2.5×0.7–1.4 mm, triangular, glabrescent. Flowers hermaphroditic, borne in (1–)3–5flowered sessile glomerules inserted on apical portion of petioles; pedicels to ca. 1.5 mm long, basally articulated; bracteoles 0.7–0.9× 0.5–0.8 mm, persistent, with long appressed [VOL 64 trichomes, especially on the median portion. Calyx ca. 6 mm long, with dense short appressed trichomes abaxially, the lobes almost equal, united at base. Corolla tube ca. 6×1.7 mm, apical lobes 5, ca. 1.5× 1.3 mm, triangular, glabrous. Disc of 5 laterally compressed glands at base of tube. Fertile stamens 5, inserted in the interior of corolla tube just beneath lobes. Ovary bilocular, hirsute, the styles ca. 3 mm long, distally free ca. 0.8 mm. Fruits ca. 1.8×1.8 cm, spheroid, densely chestnut-hirtellous, the pedicels ca. 3 mm long. Phenology.—The species has been collected with flowers in February and fruits in July. Etymology.—The specific epithet (gracile) makes reference to the slender and delicate habit of the plants, which are treelets 3–4 m tall. Habitat and distribution.—Stephanopodium gracile inhabits tall forests on soils derived from Tertiary sediments of the Barreiras formation, the so-called tabuleiro forests (Thomas & Barbosa, 2008). Although these forests cover a strip 30–100 km wide in southern Bahia state, S. gracile has been found so far only in the vicinity of Itamaraju (Bahia), close to the northern branch of the Jucuruçu River. Additional specimens examined: BRAZIL. BAHIA: Itamaraju, Fazenda Pau-brasil, ca. 5 km ao NW de Itamaraju, 17°01’S, 39°33’W, 3 Jul 1979 (fr), MattosSilva et al. 539 (CEPEC, NY, RB). This new species resembles S. blanchetianum Baill., from which it can be distinguished by the inflorescences on the apical (vs. median) portion of the leaf petiole, flowers with usually shorter (to c. 1.5 mm long) and basally articulated [vs. longer (1–) 3.5–4(−5) mm and apically articulated] pedicels, young branches with sparse short appressed (vs. dense minute sessile stellate) trichomes, and leaves completely glabrous (vs. persistently covered with minute stellate trichomes on the abaxial surface of the midrib), the blade usually membranous to subchartaceous (vs. chartaceous to subcoriaceous), with an acuminate (vs. usually obtuse or rounded, and sometimes acute) apex. From S. organense (Rizzini) Prance, which shares with 2012] FIASCHI & AMORIM: STEPHANOPODIUIM (DICHAPETALACEAE) 155 FIG. 1. Stephanopodium gracile. A. Flowering branch. B. Detail of young branch, showing indumentum. C. Leaf undersurface. D. Leaf base with inflorescence on petiole apex. E. Flower, lateral view, three corolla lobes removed. F. Corolla tube with two lobes. G. Longitudinal section of corolla tube. H. Style apex showing stigmas. I. Leaf base with fruit. (A–H from Pirani et al. 3002, SPF; I from Mattos-Silva et al. 539, CEPEC.) 156 [VOL 64 BRITTONIA S. gracile the acuminate leaf apex, the new species can be distinguished by the inflorescences on the apical (vs. median) portion of the leaf petiole, young branches with sparse short appressed trichomes (vs. with mixed minute sessile stellate and long ascending trichomes), stipules with sparse appressed (vs. dense setose) trichomes, and leaves glabrous (vs. with sparsely minute stellate and long ascending trichomes abaxially). Acknowledgments We are grateful to Sir Ghillean Prance and Jackie Kallunki for suggestions on the manuscript and the curators of CVRD, ESA, MBML, R, RB, SP, and SPF herbaria for facilitating visits and loans of specimens. Plant illustrations were drawn by Klei Sousa; the draft of Fig. 1I was drawn by Thiago R. Araujo. Financial support to PF has been provided by FAPESP (Bolsa de Pós Doutorado, grant # 2010/02814-7). AMA is supported by CNPq (Bolsa de Produtividade em Pesquisa, grant # 309303/2009-5, Universal Project, grant # 481592/2009-1 and Reflora Project, grant # 563548/2010-0) and FAPESB (Pesquisa Project, grant # APP0041/2009). Literature Cited Prance, G. T. 1972. Dichapetalaceae. Flora Neotropica 10: 1–84. ———. 1995. A synopsis of Stephanopodium (Dichapetalaceae). Kew Bulletin 50: 295–305. ———. 1997. Tapura (Dichapetalaceae) from the Mata Atlântica of Brazil. Biollandia Edición Esp. 6: 491–496. ———. 2004. Dichapetalaceae. Pp. 127–128. In: N. Smith, S. A. Mori, A. Henderson, D. W. Stevenson & S. V. Heald (eds.), Flowering plants of the neotropics. Princeton University Press, New York. Rizzini, C. T. 1952. Dichapetalaceae Brasiliensis. Revista Brasileira de Biologia 12: 97–108. Thomas, W. W. & M. R. V. Barbosa. 2008. Natural vegetation types in the Atlantic Coastal Forest of Northeastern Brazil. In: W. W. Thomas (ed.) The Atlantic Coastal Forests of Northeastern Brazil. Memoirs of the New York Botanical Garden 100: 6–20.