Five New Species of Payena (Sapotaceae) and Notes on the Genus in Borneo

Abstract

Summary. Five new species of Payena are described from Borneo: R ferruginea, P grandistipula, P kapitensis, P khoonmengiana and P kinabaluensis. P obscura Burck var. havilandii (King & Gamble) J. T. Pereira is a new combination. Notes on variation within R acuminata (Blume) Pierre and P microphylla (de Vriese) Pierre are provided. P lowiana and P glabra are reduced to synonymy under P lucida (Wall. ex G. Don) A. DC. P endertii H. J. Lam and P lucida (Wall ex G. Don) A. DC. are excluded from Borneo. A key to the Bornean species of Payena is provided. Payena has alternate and distichous leaves, tertiary venation parallel to lateral veins which descend from the margin, and the embryo with foliaceous cotyledons and copious endosperm, whereas Madhuca nearly always has spirally-arranged leaves, tertiary venation oblique or reticulate, rarely parallel and descending, and usually thick and flat cotyledons, and no endosperm or only a thin sheath. There is no comprehensive revision of Payena for Borneo, although Merrill (1921) and Masamune (1942) provided an enumeration of the Bornean species. For Peninsular Malaysia, the genus was treated by King & Gamble (1906), Ridley (1923) and Ng (1972). The papers of Lam (1925, 1927) are also important references for the genus Payena. In this revision of the genus for the Tree Flora of Sabah and Sarawak, all taxa in Borneo have been reviewed and 12 species are recognized, of which five are new. Two species, P endertii H. J. Lam and R lucida (Wall ex G. Don) A. DC. (the latter including P lowiana Pierre), previously recorded from Borneo, are now excluded. The subdivision into varieties of P acuminata (Blume) Pierre has been found impractical. Of the Bornean species, eight are endemic. Of these, P grandistipula, P kapitensis and P lamii are restricted to Sarawak, P gigas, P khoonmengiana and P kinabaluensis are endemic to Sabah, and P ferruginea and P microphylla are common throughout Borneo.