A new species of Thismia (Thismiaceae) from Yunnan, China

Thismia Griffith (1844: 221) usually grows among leaf litter in shady wet forests and comprises 47 small mycoheterotrophic species (Chiang & Hsieh 2011, Mancinelli et al. 2012). Individual plants live underground through most of the year, only emerging briefly to flower and fruit after periods of heavy rain (Ho et al. 2009). Although several species have been described in temperate regions, Thismia occurs mainly in tropical portions of America and Asia. Thismia has been typically classified in tribe Thismieae within Burmanniaceae (e.g., Jonker 1938, Maas et al. 1986, APG III 2009). However, recent molecular phylogenetic research has indicated that Thismia is sister to Tacca Forster & Forster (1775: 69) and is not nested within the clade of Burmanniaceae, which therefore supports recognition of Thismiaceae (Merckx et al. 2006). Two detailed treatments of Thismia have been published before. Jonker (1938) recognized 23 species within this genus and subdivided it into five sections. The second one, for Neotropical members by Maas et al. (1986), proposed a new subgeneric and sectional classification for Thismia, that is, three sections within subgenus Ophiomeris (Miers, 1847: 328) Maas & Maas (1986: 144) characterized by free stamens, united thecae and parietal placentas, and one section (Rodwaya (Schlechter, 1921: 38) Maas & Maas (1986: 166)) within subgenus Thismia characterized by united staminal tube, separate thecae and free placental columns. The genera Glaziocharis Taubert (1895: 66), Mamorea de la Sota (1960: 43) and Triscyphus Taubert (1895: 66) were included in section Pyramidalis Maas & Maas (1986: 161). Eleven species of Thismia have been recorded in the adjacent regions of southwestern China, Vietnam, Thailand and Burma. Three of them, T. taiwanensis Yang, Saunders & Hsu (2002: 485), T. huangii Jiang & Hsieh (2011: 138) and T. tentaculata Larsen & Averyanov (2007: 16), are found in China. Based on morphological studies of dry and living material, as well as field observations, a new species is named and described for this region.