Description from Flora of China
Stems solitary or clustered, tall to short or subterranean, ringed with conspicuous leaf scars. Leaves 4-12, pinnate or occasionally undivided; leaf sheaths closed, forming a distinct, green or yellowish crownshaft, rarely sheaths open and not forming crownshafts; rachis sometimes strongly recurved, mostly spreading horizontally; pinnae usually regularly arranged, spreading in same plane, those at apex joined with only short splits at apices, giving compound pinnae with lobed apices. Inflorescences branched to 3 orders, borne below crownshaft; prophyll present, peduncular bract absent; flowers unisexual, borne in triads of a central large female flower and 2 lateral much smaller male flowers, usually triads only at bases of rachillae, above male flowers only. Fruits usually bright red, small to moderate, ellipsoid to globose or spindle-shaped, commonly beaked, 1-seeded; endosperm ruminate; germination adjacent; eophylls bifid.
Areca triandra Roxburgh ex Buchanan-Hamilton (三药槟榔 san yao bin lang) is cultivated in Guangdong, Taiwan, and Yunnan. It differs from Areca catechu by the smaller, clustered stems, to 4 m high, and is native to India, Peninsular Malaysia, and Indochina.
About 48 species: from Sri Lanka and NE India through SE Asia to as far east as New Guinea and the Solomon Islands; one species (introduced) in China.