Aquatic and Wetland Vascular Plants of the Northern Great Plains
64. Sparganiaceae, the Burreed Family
1. Sparganium L. -- Burreed1. 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.
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Return to Family -- Sparganiaceae - The Burreed Family
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