51. Urena Linnaeus, Sp. Pl. 2: 692. 1753; Gen. Pl. ed. 5, 309. 1754.
[Malayalam ooren, to loosen or soak, alluding to retting process to extract fibers from stem tissues of U. lobata] [Malayalam ooren, to loosen or soak, alluding to retting process to extract fibers from stem tissues of U. lobata]
Steven R. Hill
Herbs, perennial, subshrubs, or shrubs, stellate-hairy or glabrate. Stems erect. Leaves: stipules early-deciduous, subulate; blade variable, sometimes ovate, [oblong or lanceolate], often 3–5-angled, -lobed, or –parted, base truncate to cordate, margins crenate [serrate], surfaces minutely stellate-hairy, with 1+ prominent, foliar nectaries (glands) on abaxial side at base of central vein. Inflorescences axillary solitary flowers or fascicles, [terminal racemes]; involucel present, bractlets persistent, 5, basally connate. Pedicels 1.5–7 mm. Flowers: calyx not accrescent, not inflated, lobes keeled, 1-veined, lanceolate, elliptic to ovate, usually acute, usually obscured by involucel; corolla shallowly campanulate to rotate, rose-pink, drying lavender; staminal column included; ovary 5-carpellate; ovules 1 per cell; style 10-branched, 2 per carpel; stigmas capitellate. Fruits schizocarps, erect, not inflated, oblate, unwinged, slightly indurate; mericarps 5, 1-celled, without dorsal spur, apex rounded, dorsal surface prominently glochidiate [smooth], otherwise hirtellous or glabrous, flat lateral surfaces striate, indehiscent. Seeds 1 per mericarp, obovoid or reniform, glabrous. x = 7.
Species 6 (1 in the flora): introduced; nearly worldwide in tropical and warm regions.