Phytotaxa 219 (3): 296–300 www.mapress.com/phytotaxa/ Copyright © 2015 Magnolia Press ISSN 1179-3155 (print edition) Article PHYTOTAXA ISSN 1179-3163 (online edition) http://dx.doi.org/10.11646/phytotaxa.219.3.10 Polyspora gioii (Theaceae), a new species from Vietnam LƯU HỒNG TRƯỜNG1, NGUYỄN THIỆN TỊCH2 & TRẦN HỢP2 Southern Institute of Ecology, Vietnam Academy of Science and Technology. Address: 1 Mạc Đĩnh Chi, District 1, Hồ Chí Minh City, Vietnam. Corresponding author’s email: hongtruongluu@gmail.com 2 Faculty of Biology, University of Science, 227 Nguyễn Văn Cừ, District 1, Hồ Chí Minh City, Vietnam. 1 Abstract Polyspora gioii (Theaceae) is described and illustrated as a new species from Hòn Bà Nature Reserve, Khánh Hòa Province, southern Vietnam. A morphological comparison between the new species and its closest congener, P. huongiana, and a key to all known species of Polyspora of Vietnam are given. Key words: Theaceae, Polyspora, new species, Vietnam Introduction Polyspora Sweet (1825: 205, cited by Sweet, 1826: 61) of the Theaceae has been traditionally placed within the genus Gordonia J.Ellis (1770: 520) but recent studies using molecular markers (Prince & Parks, 2001; Yang et al., 2004; Prince, 2007 & Zhang et al., 2014) and seed coat micromorphology (Gunathilake et al., 2014) support its delimitation from the latter. Polyspora species are characterized within the family by having sepals indistinct from the petals, stamens basally united with the corolla, oblong-ellipsoid woody capsules loculicidally dehiscent by five valves, and apically winged seeds (Sealy, 1958; Orel et al., 2013). Prior to the publication of this paper, the genus comprised about 40 species predominantly in Asia (Gagnepain, 1941; Keng, 1972; Barker, 1980; Keng, 1984; Krüssmann, 1985; Phamhoang, 1999 [all as Gordonia]; Bartholomew & Ming, 2005; Yang 2005; Ming & Bartholomew, 2007; Orel et al., 2012; Orel et al., 2013), with nine species recorded for Vietnam namely: P. ampla (Orel et al., 2013: 304), P. axillaris (Sweet, 1826: 61), P. balansae (Hu, 1963: 345), P. bidoupensis (Orel et al., 2012: 50), P. gigantiflora (Orel et al., 2012: 50), P. huongiana (Orel et al., 2012: 48), P. intricata (Orel et al., 2012: 50), P. nivea (Orel et al., 2013: 301) and P. tonkinensis (Bartholomew & Ming, 2005: 266). In 2010, Mr. Trần Giỏi informed the first author about a red-flowered Camellia-like species in Hòn Bà Nature Reserve in Khánh Hòa Province, southern Vietnam. Our surveys in the reserve up until December 2011 recorded only one population of the species with distinctive hairy leaves and twigs. Subsequent surveys between April 2012 and February 2015 included the observation of several individuals with flowers and mature fruits, all in the same population. The morphological attributes of the collections indicated that the species actually belonged to Polyspora and differed from all other known species of the genus, and it is described here as a new species. Taxonomy Polysopra gioii Lưu, Tịch et H. Trần, sp. nov. (Fig. 1) Allied to Polyspora huongiana in having hairy terminal buds, coriaceous leaf laminas, and red campanulate and pedicellate flowers but different in having sparsely yellow stellate and densely white to brown hairs on twigs, leaf petioles and adaxial laminas, obovate laminas, 5–7-lobed stigmas, 5–7-carpellate ovaries and larger capsules. 296 Accepted by Anna Trias-Blasi: 30 Jun. 2015; published: 15 Jul. 2015