Croton hancei

Croton hancei

Croton hancei is a plant of the species-rich genus Croton in the family of Euphorbiaceae ( Euphorbiaceae ). It grows endemic to the 10 km ² of small island belonging to Hong Kong Tsing Yi.

Description

Croton hancei grows as a shrub or small tree to about 5 meters Height. Young branches and buds are evenly pubescent with appressed, stellate trichomes. Older branches are hairless. The paper-like leaves are elongated - lanceolate, 8-18 cm long and 2-5 cm wide; they sit at a 2-5 mm short stalk. The leaf blade is glabrous and tapers from the base is narrowed to obtuse. The leaf margin is wholly or feingezähnt.

Bloom time is from June to August. They are in the terminal, about 3 cm long racemose inflorescences, which are supported by small bracts. The flowers are unisexual. The male flowers consist of sepals ovate, short and narrow petals and 16 stamens. The stamens are woolly. The female flowers are usually solitary at the base of the inflorescence; the five petals are elongated and each about 4-5 mm long. The ovary is almost spherical and densely hairy. The three pens are tapered in the lower part, the upper part bilobed.

Systematics and discovery history

The plant was discovered in the 1850s by HF Hance on Hong Kong Island; the first description as a new species comes from the British botanist George Bentham in 1861 and appeared in the flora Hongkongensis. After the species was long not been sighted for over a century. On 21 February 1997, it was rediscovered by members of the Hong Kong Herbarium on a steep wooded hillside on the island of Tsing Yi.

Within the species, two varieties are distinguished:

• Croton hancei var hancei.
• Croton hancei var tsoi H.S.Kiu