Medium-sized to tall trees or rarely shrubs, probably dioecious, sometimes monoecious, Indumentum of solitary simple hairs, glandular scales absent. Leaves spirally arranged, paripinnate, (1-foliolate or) l-5(-18)-jugate, without pseudo-stipules; Inflorescences in some species all axillary, in most at least partly pseudoterminal, in some truly terminal, in N. cuspidatum also rami- and Cauliflorous. Flowers actinomorphic. Sepals (4 or) 5 (or 6), free to more than halfway up connate, valvate or sometimes (when the sepals are nearly free) slightly imbricate, all equal, not petaloid, entire, outside and inside hairy, outside more sparsely and with shorter hairs than inside, not ciliate, without glands. Petals shorter than the calyx, 5 (or 6), clawed, well developed, with a bilobed scale without appendages, hairy on both sides, entire, or 1-4 reduced, or often none. Stamens 4-10, exserted in male flowers; Ovules 1 per cell, half enveloped by an outgrowth of the placenta. Fruits 1-, exceptionally 2-lobed; Seeds:
Asia-Temperate:, China South-Central (Yunnan present); Hainan (Hainan present) Asia-Tropical:, Assam (Assam present); Maluku (Maluku present); Philippines (Philippines present); Sulawesi (Sulawesi present) SE Asia: present W Malesia: present
22 species; SE Asia from Yunnan and Assam to Hainan and Malesia: W Malesia, Philippines, Celebes, and Moluccas.
The sarcotesta of a few species is eaten, but only N. lappaceum (Rambutan) is commonly cultivated as a fruit tree. The timber is hardly of any importance.
Identification is hardly possible without ± mature fruits. Therefore, under many species notes have been given regarding differences with other comparable species from the same area.