含苞草 han bao cao

Herbs, annual, to 8(-20) cm tall, in habit analogous to Centipeda, glabrous; roots thin, fusiform; stems erect, sulcate, shortly forkedly branching above, branches arcuate-spreading. Leaves alternate, sessile, falsely opposite in bifurcations of stems or gathered in 4s, lanceolate, 12-15(-45) × 3-4(-6) mm, glabrous, with 1-3(-7) denticles in upper portion, base attenuate; upper and bract leaves linear, entire or toothed. Capitula sessile, congested in 2s-4s in bifurcations of stem and its branches, 3-4.5(-6) mm in diam., polyanthous, heterogamous, globose. Involucre distichous; phyllaries of various forms, lanceolate, rhomboidal, oval, or obovate, 1.5-2.5 × ca. 0.5 mm, membranous, glabrous, greenish in center, transparent at margin with fine denticles, apex acuminate. Receptacle flat with paleae lanceolate or ovate, adnate to ovaries of female florets almost up to half of their length, free above, slightly spreading, acuminate with fine denticles at apex, almost reaching apex of corolla in length. External florets multiseriate, female, carpogenous, light yellow, tubular; corolla 0.3-0.6 mm, filiform, irregular, sometimes subregular, mainly tridentate, more rarely bidentate, sometimes 4-dentate; style ca. 0.8 mm, filiform; stigma bipartite with short lobes, ca. 0.16 mm, upright, bluntly linear, ca. 0.06 mm wide, glabrous, slightly divergent; ovary terete, 0.5-1 × ca. 0.2 mm, stalked at base, adnate to nearest palea of receptacle almost up to middle of its length, with fine globose glands and with glandular, sparse, long, horizontally spreading hairs, ovary with upright glandular hairs at apex; pappus absent; marginal female florets minutely radiate, with tridentate or bidentate corolla. Central florets 6-20, bisexual, carpogenous, tubular; corolla campanulate, ca. 0.5 mm, with 4-dentate limb. Style slightly prominent from corolla tube, flat; stigma bipartite, with short lobes, ± linear, ca. 0.12 × 0.08 mm, flattened blunt, with mammillae. Stamens 4, attached to middle of corolla tube; anthers connate into tube, surrounding style, fine, subglobose, ca. 0.25 × 0.12 mm, subtruncate above, basally with very short entire appendages, not united in pairs; filaments ca. 0.25 mm, flat, glabrous. Ovary oblong, ca. 0.5 × 0.2 mm, adnate to 2 touching paleae or to 1 palea of receptacle, more rarely not adnate, with sparse pubescence of glandular hairs. Achenes 0.5-1 mm, terete, smooth, crowned with remaining corolla, with very fine globose glands and sparse elongated glandular hairs, forked at ends and horizontally spreading, with upright hairs adaxially; marginal achenes slightly recurved, middle erect. Fl. Jul-Aug.

Silty, flooded, and sandy riverbanks or silty shallows of rivers. Heilongjiang, Jilin [Russia].