32. Citrullus Schrader ex Ecklon & Zeyher, Enum. Pl. Afric. Austral. 2: 279. 1836.
西瓜属 xi gua shu
Authors: Anmin Lu & Charles Jeffrey
Herbs, climbing, annual or perennial. Stem and branches scabrous, robust. Tendrils 2- or 3-fid, rarely simple. Leaves orbicular or triangular-ovate, deeply 3-5-partite; segments lobulate or dissected. Plants monoecious; flowers solitary, rarely fasciculate. Male flowers: calyx tube broadly campanulate, 5-lobed; corolla rotate or broadly campanulate, deeply 5-partite; segments ovate-oblong; stamens 3, inserted on base of calyx tube; filaments free, short; anthers free or slightly coherent, one 1-celled, others 2-celled; anther cells linear, sigmoid-flexuous; connective dilated, not produced; rudimentary ovary glandlike. Female flowers: calyx and corolla as in male flowers; staminodes 3, setiform or ligulate; ovary ovoid, with 3 placentas; ovules numerous, horizontal; style short, columnar; stigmas 3, thick, reniform, nearly 3-lobed. Fruit globose or oblong, fleshy or dry, indehiscent, many seeded. Seeds oblong, compressed, smooth, marginate or emarginate.
Four species: tropical and S Africa, SW Asia, E Mediterranean region; one species (introduced) in China.