Studies on Homalomeneae (Araceae) of Borneo II: TheHomalomena of Nanga Sumpa (Batang Ai) – Novel andPre-existing Taxa, and Notes on Iban Usages

摘要

Fieldwork targeting indigenous Homalomena at Nanga Sumpa, part of theBatang Ai drainage system (Sri Aman Divison, Sarawak) revealed 14 speciesof which six are novel and herewith described: Homalomena atrox P.C.Boyce,S.Y.Wong & Fasihuddin, H. clandestina P.C.Boyce, S.Y.Wong & Fasihuddin,H. hanneae P.C.Boyce, S.Y.Wong & Fasihuddin, H. sengkenyang P.C.Boyce,S.Y.Wong & Fasihuddin, H. symplocarpiifolia P.C.Boyce, S.Y.Wong &Fasihuddin, and H. vivens P.C.Boyce, S.Y.Wong & Fasihuddin. Of the sixHomalomena species present at Batang Ai for which there are pre-existingnames, two, H. borneensis Ridl. & H. humilis (Jack) Hook.f., are speciescomplexes still awaiting a full taxonomic and systematic investigation, andare treated here as morpho-taxa to which we apply the earliest applicableepithet. The remaining four species with available names have only recentlybeen described: H. geniculata M.Hotta (1967); H. vagans P.C.Boyce (1994),and H. josefii P.C.Boyce & S.Y.Wong, and H. pseudogeniculata P.C.Boyce &S.Y.Wong (2008). Additionally, two further species located during fieldwork,that while unarguably novel based on their vegetative morphology, werenot located as fertile plants and have yet to flower in cultivation; they arehere treated as sp. nov. A & B. Of the 14 species present at Batang Ai, fivehave significance in the ethnobotany of the indigenous Iban people of theAi drainage, and of these five, four are novel. A key to the Homalomena inthe Batang Ai drainage area is given, and all species are illustrated.