Slimlobe Beggarticks

Reports of Bidens tenuisecta from Maryland, Massachusetts, and New York may be based on ephemeral introductions.

Annuals, (10–)20–40 cm. Leaves: petioles 5–40 mm; blades rounded-deltate to ovate overall, 20–50+ × 15–35+ mm, (1–)2–3-pinnatisect, ultimate lobes ± linear, (2–)5–15+ × (0.5–)2–3+ mm, bases ± cuneate, ultimate margins entire, sometimes ciliolate, apices acute to attenuate, faces usually glabrous, sometimes hispidulous. Heads usually borne singly, sometimes in 2s or 3s. Peduncles 20–30(–80) mm. Calyculi of 6–12 ± appressed, linear bractlets 5–7 mm, margins scabro-ciliate, abaxial faces usually pilosulous to hirsutulous, rarely glabrous. Involucres campanulate to hemispheric or broader, (5–)6–7 × 4–8 mm. Phyllaries 8, lance-linear, 5–7 mm. Ray florets 0 or 3–6; laminae yellow, 4–6 mm. Disc florets (5–)12–20(–45); corollas yellow, 2–3 mm. Cypselae: outer red-brown, flat or weakly 4-angled, linear, 6–8 mm, margins not ciliate, apices somewhat attenuate, faces obscurely 2-grooved, often tuberculate, glabrous or ± strigillose; inner similar, blackish (sometimes with pale tips), ± equally 4-angled, linear-fusiform, 8–15 mm, margins not ciliate, apices attenuate, faces 2-grooved, glabrous or, toward tips, strigillose; pappi of 2(–3), spreading to divergent, retrorsely barbed awns (1–)1.5–3 mm.

Bidens tenuisecta , the slim lobe beggarticks, is a North American species of flowering plant in the family Asteraceae. It is native to northern Mexico (Chihuahua) and the western United States (Arizona, New Mexico, Colorado and Utah, with a few isolated populations in Texas and Idaho). There are also reports of populations in the northeastern United States (Massachusetts, New York, Maryland) but these are almost assuredly introductions.

Bidens tenuisecta is an annual herb up to 120 cm (4 feet) tall. It produces up to three yellow flower heads per branch, each had containing both disc florets and ray florets. The Plant grows in meadows and along mountain streams.