1. Helicteres isora Linnaeus, Sp. Pl. 2: 963. 1753.
火索麻 huo suo ma
Helicteres chrysocalyx Masters; H. roxburghii G. Don.
Shrubs or small trees, up to 2(-8) m tall. Branchlets stellate puberulent. Stipules linear, 7-10 mm, caducous; petiole 0.8-2.5 cm, puberulent; leaf blade broadly oblong-obovate, or almost circular, 10-12(-23) × 7-9(-17) cm, thinly leathery, abaxially densely puberulent to tomentose with mixture of stellate and simple hairs, adaxially stellate puberulent, base rounded or obliquely cordate, margin serrate, apex ± truncate with shortly acuminate tip and usually lateral lobes. Inflorescences axillary, usually 2 or 3 per axil, densely clustered, to 2 cm. Flowers 3.5-4 cm in diam. Epicalyx lobes subulate, to 7 mm. Sepals 17-20 mm, usually 4-5-lobed, lobes triangular, ± 2-lipped, densely stellate hairy. Petals red or purple, unequal in length, upper 2 larger, 1.2-1.5 cm, obliquely falcate. Androgynophore 3-4 cm, curved at tip. Stamens 10; staminodes 5, equal to filaments in length. Ovary slightly verrucose, spirally twisted after pollination. Capsule on ca. 2.5 cm stalk, cylindric, conspicuously spirally twisted, black when mature, 4-8 × (0.5-)0.7-0.9(-1) cm, apex acute, with beak to 1 cm, densely stellate puberulent at first, glabrescent. Seeds many, to 2 mm, angular, wrinkled, tomentose. Fl. Apr-Oct, fr. Oct-Jan.
Dry deciduous forests, scrub, dry grasslands on slopes; below 100-600 m. SE Hainan, S Yunnan [?Bhutan, Cambodia, India, Indonesia, Malaysia, Nepal, Sri Lanka, Thailand, Vietnam; N Australia].
The bark fiber is good for making ropes and clothing. The roots are of medicinal use.