白辛树属 bai xin shu shu

Trees or shrubs, deciduous. Winter buds naked. Leaves alternate; stipules absent; leaf blade margin serrate or serrulate. Inflorescences pendulous, branches one-sided, many-flowered; bracteoles early deciduous. Pedicel short, jointed. Flowers bisexual. Calyx tube campanulate, 5-ribbed, completely adnate to ovary, 5-toothed. Corolla lobes 5, shortly coherent at base, imbricate. Stamens 10, 5 short and 5 long or subequal in length, 1 series; filaments flattened, basally connate into a membranous tube. Ovary mostly inferior, 3--5-locular; ovules 4 per locule, erect or pendulous, placentation axile. Style elongated, subulate; stigma capitate or obscurely 3-lobed. Fruiting pedicel short. Drupes dry, ribbed or winged, with a persistent style forming distinct beak, exocarp crusty, endocarp woody. Seeds 1 or 2, fleshy; endosperm thin.

Four species: E Asia; two species in China.

Lower Taxa

• Pterostyrax corymbosus Siebold & Zuccarini
• Pterostyrax psilophyllus Diels ex Perkins