Description:

Subshrubs; stem and branches sparsely pubescent. Leaves opposite; petiole 1-1.3 cm; leaf blade ovate-lanceolate, 6-8 cm long and 2.5-4 cm wide, apex acuminate, base cuneate, margin obscurely double crenate, membranous, sparsely appressed pubescent along veins. Verticillasters continuous in spikes, 1.5-3.5 cm long. Calyx narrowly campanulate, ca. 4 mm long, 5-toothed. Corolla purplish, ca. 7 mm long, 2-lipped; lobes subequal, margin sparsely ciliate pubescent; filaments bearded. Nutlets broadly ovoid, smooth.

Distribution:

Tai Mo Shan and Ha Hang. Guangdong.

Habitat and Ecology:

In forest by streams.

A rare species discovered for the first time in Mount Parker, Hong Kong Island, between 1847 and 1850. As the population size are small, it is critically endangered. In Hong Kong, the localities of its occurrence are within Country Parks under protection.

References:

吳征鎰，1977：中國植物誌，66：369。科學出版社，北京。