Small Beggarticks

Bidens discoidea is not nearly as variable morphologically as the closely related B. vulgata or B. frondosa. It differs from B. frondosa in having smaller heads, cypselae with shorter, antrorsely barbed awns, fewer phyllaries and flowers per head, sparse indument, and leaves with fewer, more acuminate leaflets. Both B. discoidea and B. frondosa differ from B. vulgata in texture of flowers, in heads, and in shapes and surfaces of cypselae (M. L. Roberts 1982, 1983; M. G. Hickler 1999).

Annuals, (10–)20–60(–180) cm. Leaves: petioles 10–40(–60) mm; blades deltate to lance-ovate overall, 30–80(–100+) × 10–30(–80+) mm, usually 3-foliolate, leaflets petiolulate, lance-ovate to lanceolate, (10–)20–50(–100) × 5–20(–40) mm, bases cuneate, ultimate margins usually serrate, sometimes ciliate, apices acuminate to attenuate, faces glabrous or hirtellous. Heads usually borne singly, sometimes in 2s or 3s. Peduncles 10–20(–50+) mm. Calyculi of (3–)4(–5+) ± appressed, spatulate to linear, seldom foliaceous bractlets or bracts (3–)12–25 mm, margins seldom ciliate, abaxial faces usually glabrous. Involucres ± hemispheric, 4–5(–7) × 4–6(–9) mm. Phyllaries 5–7, oblong to lanceolate, 4–6+ mm. Ray florets 0. Disc florets (10–)15–20+; corollas ± orange, 1.5–2 mm. Cypselae blackish to red-brown or stramineous, ± flattened, linear to narrowly cuneate, outer 3–5 mm, inner 4–6+ mm, margins not distinctly ciliate, apices ± truncate to concave, faces ± tuberculate, antrorsely strigillose; pappi of 2 ± erect, antrorsely barbed or smooth awns (0.2–)1–2.4 mm. 2n = 24.

Coreopsis discoidea Torrey & A. Gray, Fl. N. Amer. 2: 339. 1842

Bidens discoidea, the small beggarticks, is a North American species of flowering plant in the family Asteraceae. It is widespread across eastern Canada and the eastern and central United States, from Nova Scotia west to Minnesota, south to Florida and Texas.

Bidens discoidea is an annual herb up to 180 cm (72 inches) tall. It produces as many as 3 flower heads containing orange disc florets but no ray florets. The species grows in marshes and other wet sites.

Bidens discoidea là một loài thực vật có hoa trong họ Cúc. Loài này được (Torr. & A.Gray) Britton mô tả khoa học đầu tiên năm 1893.