Pteroceras dalaputtuwa (Orchidaceae: Epidendroideae: Vandeae: Aeridinae), a new species from Sri Lanka and re-collection of Pteroceras viridiflorum after 150 years

Abstract

Pteroceras dalaputtuwa, a new species, is described from the lowland-wet zone of Sri Lanka. For the first time in the history of plant nomenclature, a new species is named after an elephant, ‘Galgamuwa Dala Puttuwa’, which was killed for its majestic ivory. The new species shows a close morphological affinity with P. philippinense from the Philippines. However, P. dalaputtuwa sp. nov. can be readily distinguished by having small and partially opened flowers (10 mm long × 5 mm wide), short petals (4 mm long × 1 mm wide), short sepals (4.9 mm long × 3.0 mm wide) and elongated rectangular-oval spur (7 mm long × 3 mm wide). P. viridiflorum, which is considered as a “Critically Endangered Possibly Extinct” [CR(PE)] orchid, is also re-collected after after a gap of nearly 150 years with a record of a new colour form (white colour variant) and, is re-described with designation of a lectotype and an epitype.

Gastrochilus flabelliformis (Blatt. & McCann) C.J.Saldanha (Epidendroideae: Vandeae: Aeridinae), an addition to the orchid flora of Sri Lanka, with taxonomic notes on Gastrochilus dasypogon (Sm.) Kuntze

“…Images and description in Sinhalage et al (2018), under Pteroceras viridiflorum (Thwaites) Holltum represent G. flabelliformis and images were taken from the same population from where the specimens for the current study were collected. The true P. viridiflorum was rediscovered from the Central Highlands of Sri Lanka after 150 years (Priyadarshana et al, 2019) and is a very different entity. Then, de Vlas (2019) reported Gastrochilus obliquus (Lindl.)…”

Research priorities and future directions in conservation of wild orchids in Sri Lanka: a review

“…The diversity of mycohetrotrophic orchids is also high in this zone. New species like Dendrobium taprobanium Priyad., Atthan., Wijew., Aberathna, Peabotuwage & Kumar (Priyadarshana et al, 2020), Pteroceras dalaputtuwa Atthan., Priyad., Wijew., Aberathna & Kumar (Priyadarshana et al, 2019) and Gastrodia gunatillekeorum Bandara, Priyankara & Kumar (Bandara et al, 2020) have been discovered in this zone.…”

“…According to the Red Data List, published in 2012, four species have not been recorded for a considerable time from their possible habitat and categorised as possible extinct species. However, Pteroceras viridiflorum (Thwaites) Holttum, considered a «Critically Endangered Possibly Extinct» (CR(PE)) orchid, was also re-collected by Priyadarshana et al (2019) after a gap of nearly 150 years, and with a record of a new colour form.…”

“…Besides, recently discovered new species are very much restricted to their type localities in a few square kilometres. Especially, the newly discovered Dendrobium taprobanium is only known from a single location whereas Pteroceras dalaputtuwa has been recorded in a small population comprising only 20 plants with an area occupancy of 2 × 2 km (Priyadarshana et al, 2019). These species grow as an epiphyte or lithophyte on lichen-and moss-covered tree trunks or wet rocks and boulders, under 80-90% shade.…”