黄顶菊 huang ding ju

Ethulia bidentis Linnaeus, Syst. Nat., ed. 12, 2: 536; Mant. Pl. 1: 110. 1767.

Annuals. Stems erect, to 100 cm tall, sparsely villous. Leaves petiolate (proximal, petioles 3-15 mm) or sessile (distal); blades lanceolate-elliptic, 50-120(-180) × 10-25(-70) mm, bases (distal) connate, margins serrate or spinulose serrate. Capitula 20-100+ in tight subglomerules in scorpioid cymes; calycular bracts 1 or 2, 1-2 mm; involucres oblong-angular, ca. 5 mm; phyllaries 3(or 4), oblong. Ray florets 0 or 1; lamina pale yellow, obliquely ovate, to 1 mm (not or barely surpassing phyllaries). Disk florets (2 or)3-8; corolla tubes ca. 0.8 mm, throats funnelform, ca. 0.8 mm. Achenes oblanceolate or subclavate, 2-2.5 mm (those of ray florets longer); pappus absent. Fl. Jul-Nov. 2n = 36.

A newly introduced weed of moist places, wastelands or disturbed sites, clay, gravel, or sands. Hebei [native to South America].