Amphicarpum

Amphicarpum is a genus of plants in the family Poaceae, native to North America.

Description

Annual herbaceous or perennial plant; erect. Stems decumbent at the base, 30–100 cm tall. Nodes glabrous, internodes hollow. defenseless plant Leaves mostly basal (A. purshii), or not; not auriculated. Leaf blades neither leathery nor flimsy; wide, or not; 5–15 mm wide, and 10–15 cm long; flats; no cross venation; persistent. hairy ligule Contraligula absent.

Plant diclinous monoecious, bisexual, with bisexual spikes (but 'chasmogamous' terminal panicle spike conspicuous without full fruiting); with hermaphrodite flowers. Cleistogamous and chasmogamous plants; with hidden leistogenes.

The inflorescence (i.e., obvious 'chasmogamous' but sterile inflorescence) paniculate; spatulate solitary spikes; pediceladas.

Taxonomy

The genus was described by Carl Sigismund Kunth and published in Révision des Graminées 1(2): 28. 1829.

Etymology

The name of the genus comes from the Greek amphikarpos (double fruit), alluding to the two kinds of spikes.

Cytology

The basic chromosome number of the genus is x = 9, with somatic chromosome numbers of 2n = 18, diploid.