美洲阔苞菊 mei zhou kuo bao ju

Conyza carolinensis Jacquin, Collectanea 2: 271. 1789.

Shrubs, erect, 1-2.5 m tall, much branched, branches densely tomentose. Petiole 1-2.5 cm; leaf blade oblong-ovate to elliptic, 6-15 × 2-6 cm, thinly tomentose and glandular on both surfaces, abaxially grayish, adaxially green, base attenuate, margin entire or nearly so, apex mucronulate-obtuse. Capitula 5-7 mm in diam. when fresh, ca. 10 mm in diam. in dried specimen, ca. 6 mm, in dense terminal and axillary corymbs; peduncle 3-8 mm. Involucre ovate to campanulate; phyllaries greenish purplish, 4- or 5-seriate, outer ones very widely elliptic to very widely obovate, 2-4 × 1.5-2 mm, tomentose abaxially, margins ciliate, apex rounded, inner lanceolate to linear-lanceolate, 4-5 × 0.5-1 mm, less pubescent to glabrous, apex acute. Receptacle flat, glabrous. Marginal florets numerous; corolla pale greenish white, pinkish toward summit, filiform, 3.5-4 mm, 3-lobed; mature achenes not seen; pappus white, slightly shorter than corolla. Central florets 20-25; corolla whitish, pinkish toward summit, 4-5 mm, sparingly glandular hairy at base; anthers obtuse at apex, shortly tailed at base; anthers and style exserted; achenes vestigial. 2n = 20.

Naturalized in disturbed ruderal sites, often on barren mudstone slopes or associated with scrubby vegetation along roads; below 100-200 m. Taiwan [native to warmer regions of the New World and W Africa].