药用狗牙花 yao yong gou ya hua

Ervatamia bovina (Loureiro) Markgraf; E. officinalis Tsiang; E. tonkinensis (Pierre ex Pitard) Markgraf; Taber-naemontana officinalis (Tsiang) P. T. Li; T. tonkinensis Pierre ex Pitard.

Shrubs or small trees 0.5-5 m tall, glabrous except for flowers. Petiole 2-8 mm; leaf blade deep green adaxially, pale green abaxially, elliptic or narrowly so, 3-21 X 1-6 cm, papery, apex caudate or acuminate; lateral veins 4-12 pairs. Cymes shorter than leaves. Flower buds with a globose head, rounded at apex. Corolla white, tube 1.2-2.8 cm; lobes obliquely elliptic, 0.5-1.5 cm, puberulent on both surfaces. Stamens inserted above middle of corolla tube. Ovary glabrous. Follicles oblong, 1.5-2.4 X 0.6-1 cm, apex mostly acuminate. Fl. May-Jun, fr. Aug-Dec.

Sparse montane forests; 200-1000 m. W Guangxi, Hainan, Yunnan [Thailand, Vietnam].