Three new species in the Achariaceae from Peninsular Malaysia

One new species of Hydnocarpus Gaertn. and two new species of Ryparosa Blume from Peninsular Malaysia are described. Hydnocarpus perakensis Pannell is most similar to H.nanus King, but its fruits are larger and the leaves are hairy. Ryparosa suboppositifolia Pannell is most like R. acuminata Merr., but its leaves are not glaucous and it has an indumentum of white medifixed hairs. Ryparosa reticulata Pannell is also most like R. acuminata Merr., but it differs in its indumentum of numerous adpressed orange-brown T-shaped hairs on the lower leaf surface, the leaves have up to 6 veins that are closer together and less steeply ascending, and the stamen filaments are free, whereas they form a tube in R. acuminata.