Genus Didymocarpus Wall. and a new record of species Didymocarpus purpureobracteatus Smith for the flora of Vietnam from Xuan Lien natural reserve, Thanh Hoa province

Abstract

Species Didymocarpus purpureobracteatus Smith is a new record for the flora of Vietnam. It was regarded as one endemic species to China, but up to now we have found it in Xuan Lien natural reserve (Thanh Hoa province). Voucher specimens were deposited in the Herbarium of the Institute of Ecology and Biological Resources, Hanoi, Vietnam (HN). This species is closed to D. poilanei but differs by bract elliptic or ovate, ca. 3-8 mm long; sepal tube ca. 8-9 mm long, sepal lobed ca. 2-3 mm long. So far, in Vietnam there were 5 species of the genus Didymocarpus Wall. recorded D. bonii, D. pulcher, D. kerrii, D. poilanei and D. purpureobracteatus.

Didymocarpus phuquocensis, a new species of Gesneriaceae from Phu Quoc Island, South-western Vietnam

“…Morphologically, the 3-verticillate petiolate leaves of D. phuquocensis are shared with several species of Didymocarpus , such as D. insulsus Craib (north-eastern, Thailand), D. tristis Craib (Chanthaburi Province, south-eastern Thailand), D. dongrakensis B.L.Burtt (northeast Thailand) D. newmanii B.L.Burtt (Chanthaburi Province, south-eastern Thailand), D. pulcher (from India, Buhtan, Nepal, China to Vietnam), D. hookeri (Assam, Arunachal Pradesh, Meghalaya and Sikkim, India), D. punduanus (Assam, Meghalaya and Nagaland, India) ( Wang et al 1998 ; Nangngam and Maxwell 2013 ; Phuong et al 2014 ; Sinha and Datta 2016 ; Roy 2017 ). Of these, the campanulate calyx of the new species is similar to D. pulcher , D. hookeri and D. punduanus , but distinguished from D. insulsus , D. newmanii and D. tristis which have the calyx 5-lobed to the base.…”

“…A critical examination of living flowers, herbarium specimens of these plants and comparison with type material and protologues of all closely-related species in Vietnam and neighbouring countries (e.g. Clarke 1874 , 1883 , 1884 ; Wallich 1829 ; Wang et al 1998 ; Pham 2000 ; Nangngam and Maxwell 2013 ; Phuong et al 2014 ; Nangngam and Middleton 2014 ; Sinha and Datta 2016 ; Roy 2017 ), suggested that these specimens were different from the other known Didymocarpus species. These plants with 3-verticillate, petiolate leaves, campanulate calyx, funnelform corolla found in Phu Quoc NP show similarities in these characters with D. pulcher , D. hookeri C.B.Clarke and D. punduanus Wall.…”

“…In Vietnam, five species of Didymocarpus have been reported, namely D. bonii Pellegr., D. kerrii Craib, D. poilanei Pellegr., D. pulcher C.B.Clarke and D. purpureobracteatus W.W.Sm. ( Pellegrin 1930 ; Pham 2000 ; Phuong and Xuyen 2012 ; Phuong et al 2014 ), but D. bonii Pellegr. [= Calcareoboea bonii (Pellegr.)…”

Didymocarpus puhoatensis (Gesneriaceae), a new species from Vietnam

“…After thorough comparisons of diagnostic morphological and anatomical features of similar taxa from China, Vietnam, Thailand and adjacent regions (Kiew 1990, Hilliard and Burtt 1995, Wang et al 1998, Burtt 1998, 1999, Weber et al 2000, Hilliard 2001, Nangngam and Maxwell 2013, Nangngam and Middleton 2014, Phuong et al 2014), it is concluded that, as its morphological characters do not fit any known species, it is a new species to science and accordingly described herein. Its morphological characters are compared with the closely related species: D. brevicalyx Nangngam & D.J.…”

“…Now approximately 70 species range from northwest India, eastwards through Nepal, Bhutan, northeast India, Burma (Myanmar), to southern China, Vietnam, Laos, Cambodia, Thailand, the Malay Peninsula and northwards to Sumatra (Weber and Burtt 1998, Weber et al 2000, Möller et al 2016). Only three species of this genus were found in Vietnam before 2012, then D. kerrii and D. purpureobracteatus were respectively reported as new record species for the flora of Vietnam (Phuong et al 2012, 2014). Didymocarpus bonii [= Calcareoboea bonii ], is now a synonym of Petrocodon bonii (Weber et al 2011).…”