Volume 9 > Part 2 > Year 2008 > Page 104 > Costaceae > Costus

3. Costus lacerus Gagnep.wfo-0000363111

Bull. Soc. Bot. France 50: 261. 1903; Maas, Blumea 25: 546. 1979; Wu & Larsen in C.Y.Wu & P.H.Raven, Fl. China 24: 321. 2000. Fig. 2: A, B.

Accepted Name : Hellenia lacera (Gagnep.) Govaerts
Phytotaxa 151: 64. 2013.

Synonyms & Citations :

Description : Stem 1–2 m, erect, usually not spirally curved, lower half of stem covered by blade-less sheaths, upper half leafy; sheath ca 4 cm, green, densely puberulous when young later glabrescent; petiole 5–10 mm. Leaf blade elliptic, to lanceolate-oblong, 20–40 by 6–15 cm, base rounded to cordate, apex acute to acuminate, upper side glabrescent, lower side sparsely to densely villous. Inflorescence terminal to about 10 cm long, 5–7 cm wide on a short, usually curved peduncle. Bracts 12–15 mm long, each subtending 1 flower, ovate, acute, green often flushed with red, with a narrow red, fleshy protuberance up to 5 mm long below the apex, glabrous to hairy, when old breaking into fibres. Bracteoles ca 10 mm, ovate, acute with ciliate margin. Flower: calyx green turning red, much longer than bract, up to 3 cm, with 3 reddish, unequal teeth, split to base on one side. Corolla tube shorter than calyx, lobes 3–5 by 2.5—3 cm, white or pinkish. Labellum 69 cm across, white to pinkish with a median yellowish band. Stamen petaloid, oblong ca 5 by 1.2 cm, filament ca 12 mm broad. Ovary flattened, ca 9 mm broad. Capsule ellipsoid, ca 2.4 cm long, hirsute crowned by the persistent calyx.

Thailand : NORTHERN: Chiang Mai (Doi Suthep, Doi Inthanon, north of Doi Chiang Dao), Mae Hong Son; EASTERN: Loei (Na Haeo).

Distribution : Bhutan, N India (type), China (Yunnan), Vietnam, Laos.

Ecology : In open grasslands in deciduous forests, and along roadsides, often in moist places and together with Costus speciosus, from 500–1,500 m alt. (in Yunnan, up to 2,200 m).