New Orchids from Gunung Mulu National Park, Sarawak

Abstract

Summary. Fifteen new taxa are described from Sarawak, Borneo, including the new saprophytic genus Muluorchis. Most of the material was collected during 1977 and 1978 by members of the Royal Geographical Society expedition to Gunung Mulu. Specialist groups such as begonias, gesneriads, gingers, palms, ferns and fungi are currently under study and several new taxa have already been described from the park (Jermy, ed. 1980, Jermy & Kavanagh, ed. 1982). An account of the expedition has been published by Hanbury-Tenison & Jermy (1979). The following new taxa were identified whilst preparing a preliminary checklist of the Orchidaceae of the Gunung Mulu National Park to be published soon. Muluorchis J. J. Wood gen. nov. (Spiranthoideae-Goodyerinae), a ceteris generibus hujus subtribus caulibus ramosis aphyllis brunneis ramentaceis (Lecanorchi similibus), sepalis ramentaceis diversa. Typus: M. ramosa J. J. Wood. Herbae aphyllae saprophyticae. Caules identidem ramificati, ramentacei, vaginulas parvas numerosas gerentes. Inflorescentiae terminales, 6-12florae, aut laxae aut subdensae. Flores minuti, albi, haud resupinati. Sepala reflexa, ramentacea. Labellum cymbiforme, apice decurvo, glabrum. Columna rostrata, rostello aciculari, anthera dorsali, acuminato-rostrata; pollinia 2, sectilia. This curious monotypic saprophytic genus is known only from four collections made on Gunung Mulu. The remarkable branching habit is unique within the Spiranthoideae, a large subfamily of terrestrial genera with centres of distribution in Central and South America and South East Asia. Members of Spiranthoideae always have a column with a dorsal, erect anther which is subequal to the rostellum and pollinia that are normally apically attached to the viscidium. The branching stems are very similar to species of Lecanorchis B1. (subfamily Epidendroideae, subtribe Lecanorchidinae) also recorded from the Park, but the white non-resupinate starry flowers have a column structure which at once places it in subfamily Spiranthoideae, subtribe Goodyerinae (Dressler 1981). The subtribe Goodyerinae, although pantropical, is primarily tropical Asian and contains 37 genera each falling into one of two alliances depending on whether the stigma is entire or bilobed. The majority of genera, including Muluorchis, have an entire stigma. Non-resupinate flowers, i.e. with the lip borne uppermost, are rare in the Goodyerinae and among the Asian genera are only found in Hetaeria, Macodes and Muluorchis. The lip lacks any of the typical emergent glands commonly found in the Goodyerinae. Another striking feature of Muluorchis is the ramentaceous indumentum present on the stems, inflores