Thismia thaithongiana (Dioscoreaceae: Thismieae), a new species of mycoheterotroph from an unusual habitat

Abstract

With more than 60 currently accepted species, Thismia Griffith (1844: 221) is the largest genus of the tribe Thismieae of Dioscoreaceae (sensu APG 2016, or Thismiaceae of other authors). The genus is widely distributed mainly in the tropical and subtropical regions with a concentration of species in Southeast Asia (ca. 30 species) including the Malay Peninsula, Sumatra, Java, Borneo, Thailand and Vietnam. In last decade, many new taxa have been described from Southeast Asia (e.g. Larsen & Averyanov 2007, Chantanaorrapint 2008 2012, Tsukaya & Okada 2012, Dančák et al. 2013, Nuraliev et al. 2014 2015, Truong et al. 2014, Tsukaya et al. 2014, Chantanaorrapint & Sridith 2015, Hroneš et al. 2015, Chantanaorrapint et al. 2016, Sochor et al. 2017). Members of the genus are small mycoheterotrophic herbs with a highly reduced habit and usually grow among leaf litter in shady wet forests.