14. Ranunculus parviflorus L. (stickseed crowfoot, small-flowered
crowfoot)
Pl. 520 d, e;
Map 2380
Plants annuals.
Roots not tuberous. Stems 10–30 cm long, erect to loosely ascending, not
rooting at the lower nodes, moderately to densely pubescent with fine,
spreading hairs, without bulbils, the base not bulbous. Basal leaves present at
flowering, long-petiolate, the blade 1.5–3.2 cm long, 1.0–2.4 cm wide,
heart-shaped, kidney-shaped, or semicircular, simple, the base shallowly to
deeply cordate or less commonly broadly rounded, the lobes sometimes again
3-lobed, the lobes more or less rounded at the tip, the margins otherwise
entire or sharply toothed. Stem leaves progressively and less divided from the
stem base to tip, mostly short-petiolate or sessile. Sepals 5, 1.5–2.0 mm long,
reflexed from the base (lacking a transverse fold), more or less plane. Petals
1–5 or rarely absent, when present 1.1–1.8 mm long, 0.2–0.7 mm wide, narrowly
obovate to narrowly oblong-obovate, shorter than the sepals, yellow. Style
present. Head of achenes 3–5 mm long at maturity, more or less globose, the
receptacle glabrous. Achenes 1.7–2.0 mm long, the dorsal margin bluntly
thickened, the wall thick, the lateral faces covered with hooked hairs, the
beak flattened, triangular, strongly curved or hooked. 2n=32.
March–June.
Introduced,
scattered in the southern half of the state, mostly abundantly along the
southern tier of counties (native of Europe, Asia; introduced in the eastern
U.S. west to Missouri and Texas, also the western U.S. from Washington to
California; Canada, Australia, Pacific Islands). Upland prairies; also
pastures, old fields, ditches, lawns, and open, disturbed areas.