Longstalk Greenthread

Perennials or subshrubs (may flower first year), 20–40+ cm. Cauline leaves mostly crowded over proximal ¹/4–¹/2 of plant heights, internodes mostly 5–25+ mm; lobes mostly linear to filiform, 5–25(–45+) × 0.5(–1) mm. Calyculi of 5 ovate bractlets 1–3 mm. Ray florets 0. Disc corollas yellow, sometimes with red-brown nerves, throats equal to or longer than lobes. Cypselae 2–3 mm; pappi usually 0, rarely 0.1–0.3+ mm. 2n = 40.