Vigorous woody vine or climbing shrub, 3-8(-30) m; Leaves ovate to oblong, apex ± acuminate, acutish, base cuneate to obtuse, rarely rounded or subcordate, subequal, chartaceous to subcoriaceous, caducous-puberulous especially at the nerves beneath, the hairs persisting in the nerve axils as domatia, serrulate-crenulate or crenate, sometimes subentire, 8-18(-24) by 4-8 (-10) cm, nerves 1(-2) basal or slightly supra-basal, and 3-4 upper pairs, all arched and steeply ascending, veins and veinlets densely reticulate, slender but prominent on both faces; Stipules small, knob-like. Flowers solitary, or mostly crowded into glomerules, these spaced along the slender to filiform rachis. Sepals ovate, greenish white or yellowish, hairy on both sides, c. 1.5 mm. Petals ovate, thin, c. 1 mm. Panicles loose, composed of a few axillary or terminal spike-like racemes, pendent, puberulous, 10-25 cm. Capsule obovoid-ellipsoid in outline, 5-winged, green, later dark brown, caducous-pubescent, 2.2-3(-3.5) by 1.3-1.8 cm; Seed 1, subcylindrical, acuminate, lengthwise grooved, 12-15 by 5-6 mm.
Micronesia (Palau Is.), Melanesia (New Ireland, Duke of York I., New Britain, Solomon Is.), in Malesia: Malay Peninsula (Penang to Malacca), North Borneo, W. Central and N. Celebes, Moluccas (Talaud Is., Ceram, Sula Is., Ambon), New Guinea. .
The rather hard stem splits easily into pieces, and apparently for this reason is used in New Britain for tying thatch. RUMPHIUS under his ‘Sinapistrum’ says, that crumpled leaves give a strong smell of mustard, and are used to cure ulcers.
HEYNE - in Nutt. Pl. 1950: 987
PAX - in E. & P., Nat. Pfl. Fam. III. 1890: 117
SLOOT. - in Bull. Jard. Bot. Btzg. 1925: 364
HOOK.f. - in Fl. Males. 1954: 63
ENGL. - in E. & P., Nat. Pfl. Fam. 3. 1893: 238, 257
SLEUM. - in E. & P., Nat. Pfl. Fam., ed. 2, 20b. 1942: 393
HOLTH. & H. J. LAM - in Blumea. 1942: f. 7
SLEUM. - in E. & P., Nat. Pfl. Fam., ed. 2, 20b. 1942: f. 117 (habit) & 118 (wood anat, embryol.)
HOOK.f. - in Fl. Br. Ind. 1888: 673
HOOK.f. - in Blumea. 1969: with extensive bibliogr.
RIDL. - in Fl. Mal. Pen. 1922: 435
HALL.f. - in Med. Rijksherb. 1910: 9
PEEKEL, Fl. Bismarck Arch. MS: fig.
DAHL - in J. Arn. Arb. 1955: f. 2 & 2A