Amphicarpum amphicarpon

HABIT Annual. Culms erect; 30–80 cm long. Leaf-sheaths hispid. Ligule a fringe of hairs. Leaf-blades linear, or lanceolate; 10–15 cm long; 5–15 mm wide. Leaf-blade surface pilose; hairy on both sides; with tubercle-based hairs. Leaf-blade margins tuberculate-ciliate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 3–20 cm long; contracted about primary branches. Primary panicle branches 1.5–12 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acuminate; 7–8 mm long; falling entire.

GLUMES Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume lanceolate; 6–7 mm long; 0.9 length of adjacent fertile lemma; membranous; without keels; 7 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 5 -veined; acute. Fertile lemma oblong; 7–8 mm long; indurate; much thinner on margins; without keel; 5 -veined. Lemma margins flat. Lemma apex apiculate. Palea indurate.

FLOWER Anthers 3.

CLEISTOGENES AND VIVIPARY Cleistogenes present; underground.

DISTRIBUTION North America: northeast USA and southeast USA.

NOTES Paniceae. WDC.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.