Amphicarpum amphicarpon

Plants annual. Culms 30-80 cm, erect. Leaves mostly basal; sheaths hirsute; blades 10-15 cm long, 5-15 mm wide, hirsute on both surfaces, margins ciliate. Subterranean spikelets 7-8 mm, acuminate. Aerial panicles 3-20 cm; aerial spikelets 4-5 mm, ellipsoidal. 2n = 18.

Amphicarpum amphicarpon grows in sandy pinelands of the eastern United States. It used to be known as A. purshii Kunth, but A. amphicarpon has priority. February 2009: The records from Florida have been removed from the map because, after diligent searching, Bruce Wunderlin and Richard Wunderlin were unable to find any specimens supporting the present of Amphicarpum amphicarpon in Florida. Barkworth had not kept a record of the specimens on which her report was based.

Erect slender annual 3-7 dm; sheaths striate, hirsute; blades 5-15 cm, hirsute, the uppermost much reduced; panicle exsert, 5-15 cm, simple or with a few main branches, the branchlets appressed; spikelets elliptic, glabrous, 4 mm; subterranean spikelets 6-7 mm, sparsely hairy; 2n=18. Wet pine-barrens; N.J. to Ga. (A. purshii)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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