The Bornean Lithocarpus Bl. section Synaedrys (Lindl.) Barnett (Fagaceae): its circumscription and description of a new species

The Bornean species of Lithocarpus Bl. section Synaedrys (Lindl.) Barnett (Fagaceae) are discussed in terms of their unifying characteristics, and keys to the species are provided. A novel morphological feature present in the genus, where the seed in the mature fruit is enclosed by a lignified and thickened receptacle, is illustrated. A new species, L. palungensis Cannon & Manos, is described. It can be distinguished from L. pulcher (King) Markgr. by its submontane distribution, prominent reflexed cupular spines, present at all stages, and broadly oblong leaves with scattered open fasciculate trichomes on the abaxial surface. Foliar trichome types present within the section are also described. Distinctiveness of fruit wall and receptacle shape, as described by two-dimensional elliptic Fourier transformation, is demonstrated by principal components analysis.