Mycoheterotrophic plants of Tama Abu Protected Forest, Ulu Baram, Sarawak

A 10-day botanical survey was conducted during the Sarawak Heart of Borneo (HoB) Scientific Expedition in Tama Abu Protected Forest, Ulu Baram, Sarawak, from 15th to 25th August 2017. The scientific expedition was organized by Sarawak Forestry Department, which aim to document the variety of rich flora and fauna in Tama Abu Protected Forest. From the survey, four (4) families of mycoheterotrophic plants of angiosperms group were discovered, they are Burmanniaceae, Orchidaceae, Polygalaceae and Triuridaceae. These comprise of seven (7) genera and 12 species reported for this protected forest. Among the species, Epirixanthes confusaand Gymnosiphon aphyllusare recorded forthe firsttime inSarawak.Two species endemics to Bornean region, Cystorchis saprophyticaand Epirixanthes confusa. Orchidaceae and Polygalaceae families are the most diverse families, with four recorded species for each. Most of the species recorded from pristinemixed dipterocarp forest with high humidity, except Gymnosiphon aphyllusand Sciaphila winkleri. These findingscould be underrepresented the richness of mycoheterotrophicplants in Tama Abu, as this group of plant is easily over-looked due to their tiny size and dull colour that blend into the background colour of forest floor. The diversity of mycoheterotrophicplants in Borneo is expected to be high as the environment in Borneo is suitable for them to grow. However, most of the mycoheterotrophicplants are under-studied as they were rarely collected