Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
9. Ranunculaceae, the Buttercup Family
3. Myosurus L. -- Mouse-tail
1. Myosurus minimus L.
Small, glabrous, acaulescent annual 4-15 cm tall, with fibrous roots and a basal
tuft of narrow, linear leaves mostly less than 1 mm wide. Flowers
small, inconspicuous, usually few to many, borne singly above the leaves on
slender peduncles, becoming more conspicuous in fruit; sepals greenish,
usually 5, erect, spurred downward at the base, deciduous, 1.5-3.5(5.5) mm long,
the blade lightly 3(5)-nerved on the back, usually longer than the spur; petals
usually 5, sometimes none, inconspicuous, whitish or pinkish, about equaling
the sepals; stamens 5-10; pistils many, borne on an elongate receptacle,
ripening as a slender spike of usually more than 100, closely adherent, angular
achenes; the achene bodies 1-2 mm long, with a sharp dorsal keel that
extends beyond the body as an inconspicuous beak to 0.5 mm long, the beaks appressed
in the spike; mature spike of achenes 1-6 cm long. Late Apr--Jun. Wet
to moist places, sometimes in shallow water, usually where water stands only
temporarily; scattered and probably more common than records indicate, as the
plant is early and easily overlooked; (Ont. to B.C., s to FL, TX and CA; also
s Europe, Asia and Australia).
A similar species, Myosurus aristatus Benth. ex Hook., has been recorded
for Slope, Ward and Williams Cos., ND, and Daniels Co., MT. This plant also
occurs in temporarily wet places, apparently in prairie. It differs from M.
minimus mainly in the following ways: Sepals 1-nerved or rarely
with 2 faint lateral nerves; achenes 20-50(90), rather loose in the
spike, the achene bodies with a broad low keel and usually 2 marginal
ridges on the back, the beaks conspicuous, 0.5-1.5 mm long, divergent from
the spike; mature spike of achenes 0.5-2.5 cm long
Previous Species -- Caltha palustris L.
Return to Family -- Ranunculaceae -
The Buttercup Family
Next Species -- Ranunculus cardiophyllus Hook.