Hopi Tea Greenthread

Thelesperma megapotamicum sometimes persists after plantings outside its natural range in the flora area and may become established (e.g., in California).

Perennials or subshrubs, (20–)30–80+ cm. Cauline leaves ± scattered over proximal ¹/2–³/4 of plant heights, internodes mostly 40–100 mm; lobes mostly linear to filiform, sometimes oblanceolate, 20–40(–50+) × 0.5–1(–2.5) mm. Calyculi of 3–5+ ovate to oblong bractlets 1–2(–3) mm. Ray florets 0. Disc corollas yellow, often with red-brown nerves, throats shorter than lobes. Cypselae 5–8 mm; pappi 1–2(–3) mm. 2n = 22, 44.

Bidens megapotamica Sprengel, Syst. Veg. 3: 454. 1826; Thelesperma gracile (Torrey) A. Gray