Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
64. Sparganiaceae, the Burreed Family
1. Sparganium L. -- Burreed
1. Sparganium chlorocarpum Rydb. -- Greenfruit burreed
Erect or sometimes lax and trailing in the water, at least the upper leaves
and inflorescence emergent, 1-6 dm tall (to 10 dm or more long when deeply submersed).
Leaves yellow-green, flat to keeled, mostly 3-5(7) mm wide, often scarious-margined
toward the base but not strongly dilated. Inflorescence 1-2 dm long,
unbranched, one or more of the lower pistillate heads usually peduncled, at
least one supra-axillary; staminate heads usually 2-5, ca. 1.5 cm in
diameter at anthesis; anthers linear, 1-1.4 mm long; pistillate heads
1-4, (1)1.5-2.5 cm in diameter at maturity; stigma 1, linear, 1-1.5(2)
mm long. Achenes stipitate in the head, on stipes 2-3 mm long, green
to brown-olivaceous on the upper 1/2, lighter and usually reddish-brown spotted
on the lower 1/2, fusiform, rounded on the sides, slightly constricted at the
middle, the body 3.5-5 mm long, the beak with the stigma 2-4.3 mm long, curved,
the persistent perianth of 4-5 scales reaching to ca. 2/3 the length of the
achene. Mid Jun--Aug. Shallow water or mud of marshes, streams, ditches and
ponds, where the water is fairly fresh; occasional from e MT to e ND and ne
SD; (Newf. and Que. to n ID, s to WV, IN, IA, SD and MT).
Reports of S. americanum Nutt. and S. angustifolium Michx.
for our region are apparently based on misidentifications of this species.
See also the comments under the following.
Return to Family -- Sparganiaceae - The Burreed
Next Section -- Sparganium emersum Rehm.