Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
51. Alismataceae, the Water Plantain Family
3. Sagittaria L. -- Arrowhead, duck potato
5. Sagittaria latifolia Willd.
Emergent to emersed perennial 2-8 dm tall, or much longer when growing in deep
water, rhizomatous and with tubers in autumn. Leaves highly variable
depending on water depth, emersed leaf blades sagittate, mostly 8-40 cm long,
0.4-15 cm wide, the lobes narrow and linear on plants of deep water to broadly
deltoid on emersed specimens, the basal lobes shorter to longer than the terminal
one; submersed phyllodes, if produced, apparently gone by flowering time. Inflorescences
1-few, simple or rarely branched from the lowest node; bracts bluntly
acute to obtuse, 0.5-1 cm long; pedicels slender, 0.3-3.5 cm long, ascending
to spreading. Flowers male above and female below or seldom all of one
sex; sepals ovate, 4-10 mm long, broadly rounded, reflexed in fruit;
petals white, 7-20 mm long; filaments glabrous, longer than the
anther. Fruiting heads globose to somewhat flattened, 1-2.5 cm across;
achenes 2.5-4 mm long, dorsal wing rounded over the top of the achene,
ventral wing gradually widened upward to meet the beak; beak projecting
horizontally, tapered, 1-1.5(2.5) mm long. Jul--Sep. Mud or shallow water of
rivers, streams, lakes and marshes; frequent in e ND, e and s SD and NE; (N.S.
and Que. to B.C., s to S.Amer.).
Many records of S. latifolia for the w and c parts of ND and SD and
e WY are based upon misidentifications of S. cuneata.
Previous Section -- Sagittaria graminea Michx.
Return to Family -- Alismataceae -
The Water Plantain Family
Next Section -- Sagittaria rigida Pursh