Lemmon's Beggarticks

Annuals, (10–)15–25(–30+) cm. Leaves: petioles 10–20 mm; blades either oblanceolate to linear, 5–15+ × 1–2+ mm, or rounded-deltate overall, 10–25(–60+) × 15–25+ mm, (1–)2–3-pinnatisect, ultimate lobes oblanceolate to spatulate or linear, 5–15+ × 0.5–5 mm, bases ± cuneate, ultimate margins entire, sometimes ciliolate, apices obtuse to acute, faces glabrous. Heads usually borne singly, sometimes in open, ± corymbiform arrays. Peduncles 10–20(–90) mm. Calyculi of (1–)3–4 appressed to spreading, spatulate to linear bractlets or bracts 3–10(–25+) mm (sometimes foliaceous: pinnate, lobes 3–5+, linear), margins ciliolate, abaxial faces usually glabrous, sometimes sparsely hispidulous. Involucres ± campanulate to cylindric, 2–3(–8) × 2(–3)[–4] mm. Phyllaries (3–)5, oblong to lanceolate orlinear, (2–)3–8 mm. Ray florets 0 or 1(–3+); laminae whitish, 1–1.5(–3+) mm. Disc florets (3–)5–9; corollas whitish to yellowish, 2–2.5 mm. Cypselae: outer red-brown (sometimes with lighter blotches), ± equally 4-angled, linear-fusiform, 5–6(–8) mm, margins not ciliate, apices ± attenuate, faces 2-grooved, usually glabrous; inner similar, 10–14 mm; pappi of 2–3 erect, retrorsely barbed awns 1–2(–3) mm.

Bidens lemmonii (Lemmon's beggarticks) is a North American species of flowering plant in the family Asteraceae. It is native to the southwestern United States (Arizona, New Mexico) and Mexico (Sonora, Chihuahua, Durango, Sinaloa, Michoacán, Baja California, Baja California Sur).

Bidens lemmonii is an annual herb up to 30 cm (12 inches) tall. It produces flower heads sometimes one at a time, sometimes in a group of several, each containing yellow disc florets and (usually) white ray florets. The species grows in wet seeps on rocky mountainsides.

The species is named for John Gill Lemmon (1831 or 32-1908), husband of American botanist Sara Plummer Lemmon (1836–1923).