• Scientific Name: Calotropis gigantea (L.) W.T.Aiton
• Ref: Hortus Kew. 2:78. 1811
• Synonym: Asclepias argentata Noronha; Asclepias gigantea L.; Madorius giganteus (L.) Kuntze; Periploca chinensis Decne.; Periploca cochinchinensis Lour.; Streptocaulon cochinchinense (Lour.) G.Don
• English Common Name: crown flower, giant milkweed, giant calotrope
• Chinese Common Name: 牛角瓜 niújiǎo∙guā, 羊浸树 yángjìnshù
• Family: Apocynaceae
• Genus: Calotropis
• Distribution: Woods of dry areas, stream banks; 0-1400 m. Guangdong, Guangxi, Hainan, Sichuan, Yunnan [India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Pakistan, Sri Lanka, Thailand, Vietnam; tropical Africa]
• Photo: 06/21/2009, South China Botanical Garden, Guangdong

Shrubs 1-5 m tall. Petiole 1-4 mm; leaf blade obovate-oblong or oblong, 7-30 × 3-15 cm, base cordate, apex obtuse, cottony tomentose when young, frequently glabrescent and glaucous green; lateral veins 4-8 pairs. Cymes umbel-like, with fine woolly hairs; peduncle robust, 5-12 cm. Pedicel thick, 2-5 cm. Calyx almost flat, 1.2-1.5 cm in diam. Flower buds cylindric. Corolla usually purplish or lilac with paler greenish base, 2.5-3.5 cm in diam., fleshy, glabrous; lobes ovate, 1-1.5 × 0.6-1 cm, spreading or reflexed, margin revolute. Corona shorter than gynostegium. Follicles obliquely elliptic to oblong-lanceolate in outline, 5-10 × 2.5-4 cm, both ends incurved. Seeds broadly ovate, 5-7 × 3-4 mm; coma 2.5-4 cm. Fl. almost throughout the year. 2n = 22. (Flora of China)

06/21/2009, South China Botanical Garden