Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
9. Ranunculaceae, the Buttercup Family
4. Ranunculus L. -- Buttercup, crowfoot
7. Ranunculus longirostris Godr. -- White water-crowfoot
Submersed, mostly glabrous perennial. Stems floating, elongate, flexuous,
mostly 3-8 dm long, simple or sparingly branched, rooting from the lower nodes.
Leaves all cauline, the blades finely divided into filiform segments,
once or twice trichotomous, then dichotomous, globular in outline, reniform
when flattened, 1-2 cm long, 1.5-3 cm wide; petioles consisting of the inflated
stipular leaf bases, 2-4 mm long, glabrous or pubescent. Flowers solitary
from the axils in the upper portion of the stem, white; sepals 5(6),
purplish-green, spreading, 2-3.5 mm long, deciduous shortly before the petals;
petals 5, white, suffused with yellow at the base, 4-9 mm long; stamens
10-20. Achenes (7)15-25, in a hemispheric to globose head 3-5 mm long,
3-6 mm thick; achene body obovoid, transversely ridged, glabrous or slightly
hispid, averaging 1.5 mm long, the beak prominent, slender and straight, 0.7-1.1
mm long (often shorter when dried); receptacle 1-2 mm long, pubescent;
peduncles recurved in fruit, 1-5 cm long. Jun--Jul, occasionally in Aug--Sep.
Slow streams, ponds, marshes and water-filled ditches, usually in calcareous
water; occasional in the n part, common s; (Que. to Sask., s to DE, TN, AL,
AR, TX, NM, ID and NV). R. aquatilis L., misapplied.
Previous Species -- Ranunculus hispidus Michx.
-- Marsh buttercup
Return to Family -- Ranunculaceae -
The Buttercup Family
Next Species -- Ranunculus macounii Britt.
-- Macoun's buttercup