Roscoea tibetica Batalin

Flowering from June to July.

Roscoea tibetica is close relative of Roscoea kunmingensis, but differs from the latter in its leaves obscurely to densely hairy especially when young (vs. glabrous), bracts elliptic (vs. tubular), lateral staminodes oblong, 1-1.3 cm (vs. narrowly obovate-cuneate, ca. 1.4 cm).

Roscoea tibetica is occurring in Sichuan, Xizang, Yunnan of China, Bhutan, India.

Phylogeny of Roscoea (Zingiberaceae) was inferred from sequence data of the internal transcribed spacers (ITS) of the nuclear ribosomal DNA (nrDNA) (Ngamriabsakul et al., 2000). The results suggest that Roscoea was monophyletic and divided into two sister clades which correlate with geography: a “Chinese” clade and a “Himalayan” clade.

Plants 5-15 cm tall. Leaves 1-3, forming a rosette; ligule obscure, ca. 0.5 mm; leaf blade elliptic, widest near base, 2-6 cm long, 1-2.5 cm wide, obscurely to densely hairy especially when young, apex obtuse to acute. Inflorescence enclosed by leaf sheaths; bracts elliptic, 2.2-4 cm. Flowers purple or violet, held just above leaf rosette. Calyx brown spotted, 3-4 cm, apex 3-toothed. Corolla tube 4-5 cm; central lobe oblong, cucullate, 1.5-1.7 cm long, ca. 8 mm wide, apex apiculate; lateral lobes lanceolate, 1.5-1.8 cm long, 4-5 mm wide. Lateral staminodes oblong, 1-1.3 cm. Labellum slightly reflexed, obovate 1.4-2.5 cm long, 0.8-1.8 cm wide including claw, usually deeply lobed for more than 1/2 its length. Anther cream; connective spur 3-7 mm. Ovary cylindric, ca. 1.5 cm.

The chromosomal number of Roscoea tibetica is 2n = 24 (Chen et al., 1988; West and Cowley, 1993).

Growing in Pinus forests, scrub, alpine meadows; 2400-3800 m.