1. Falcaria vulgaris Bernh. (sickleweed)

F. sioides (Wibel) Asch.

Pl. 207 a–d; Map 860

Plants biennial or perennial, glabrous, glaucous, with long taproots. Stems 30–100 cm long, erect or ascending. Leaves alternate and sometimes also basal (1 or more basal leaves sometimes present at flowering), the basal and lowermost stem leaves usually long-petiolate, the median and upper leaves short-petiolate or sessile, the sheathing bases not or only slightly inflated. Leaf blades 1–35 cm long, broadly oblong to triangular-ovate in outline, those of the basal and lowermost stem leaves ternately or ternately then pinnately 1–2(–3) times compound or lobed, less commonly ternately lobed or compound then 2-lobed, the main axis (rachis) often winged below the attachment points of the leaflets, the ultimate leaflets or segments 20–250 mm long, narrowly oblong to linear, narrowed at the base, tapered to a sharp point at the tip, the margins finely toothed (the teeth with minute, thickened, spiny tips); the leaflets of the median and upper stem leaves progressively reduced, 1 or 2 times ternately compound or lobed, the uppermost leaves often simple. Inflorescences terminal and axillary, compound umbels, mostly long-stalked. Involucre of 3–12 bracts, these shorter than the rays, spreading to loosely reflexed at flowering, linear to narrowly lanceolate, entire, with sharply pointed tips. Rays (4–)10–25, 0.8–4.0 cm long. Involucel of 3–11 bractlets, these shorter than to longer than the flower stalks, similar to the bracts but smaller. Flowers 5 to numerous in each umbellet, the stalks 4–10 mm long. Sepals minute triangular teeth. Petals obovate, rounded or shallowly notched at the tip, white. Ovaries glabrous. Fruits 2–5 mm long, narrowly oblong in outline, flattened laterally, glabrous, brown with pale ribs, the mericarps often somewhat arched or curved, with 5 broad, flattened ribs (wider than the spaces between them), these lacking wings. 2n=22. July–September.

Introduced, uncommon, known thus far only from Boone and Jackson Counties (native of Europe, Asia; introduced widely but sporadically in the northeastern U.S.). Roadsides, fencerows, and open, disturbed areas.