Description

Key Characters:

Growth Form: Annual or perennial herbs 0.2–1.5m tall, pubescence predominantly of simple and appressed, bilateral, 4–armed hairs.

Stems:

Roots:

Leaves: Leaves simple. Alternate. Blades lanceolate to broadly ovate, usually 2.5–5(–11) cm long, rarely slightly 3–lobed. Apex acute. Base truncate to broadly cuneate. Margins serrate to dentate. Petioles shorter than blades. Stipules linear to triangular, usually curved, +/- persistent.

Flowers: Flowers axillary, 1–3 together, or in racemose glomerules, sometimes congested apically; involucral bracts 3, lanceolate, 4–6 mm long, adnate basally to calyx. Flowers bisexual (perfect). Calyx composed of connate sepals, 5-lobed, 5–7mm long at anthesis, 7–12 mm long in fruit, often angled in bud, the lobes valvate in bud. Corolla actinomorphic to moderately zygomorphic, pale yellow to yellowish orange, rotate, corolla of 5 petals, obovate, 15–24 mm in diameter, distinct from each other but adnate at base to staminal column, convolute in bud. Stamens 5 to numerous, monadelphous, forming a staminal column, up to 2.5 mm long, shorter than corolla and same in color, glabrous, terminated by filaments; anthers monothecal. Pollen globose, echinate. Ovary superior, carpels 5-18, borne in a single whorl or rarely seemingly superposed whorls, placentation axile; ovules 1 per carpel, ascending; style exceeding the staminal column, branches as many as carpels; stigmas terminal, capitate.

Fruit: Schizocarps reddish brown; 5–7(–9) mm in diameter; mericarps (9)10–14(15); 3–3.5 mm high and 3.5-4 mm wide; indehiscent; with a ventro–apical spine 0.8-1(-2) mm long and 2 dorso–apical cusps; 0.5–1.2 mm long; hispid apically; endoglossum absent. Seeds 1.5–2 mm long; reddish brown to black; subreniform; compressed; glabrous; with or without endosperm.

Ploidy: 2n = 24

Habitat: Naturalized in disturbed sites.

Elevation Range: 3–610 m.