rhachis

A tree 20–60° high; leaflets 4–9 pairs, obliquely lanceolate, sharply acuminate, entire, 1½–3´ long; the rhachis of the leaf not winged; flowers white, in a large panicle, fruit mostly globose, 6´´ broad.

Otherwise nearly as in Vicia.—Our species are perennial and mostly smooth plants, the rhachis of the leaves in some not produced into a tendril.

Achene lenticular, the edge turned to the rhachis; spikelet flattened, many flowered; rhachis narrow, not winged.

Style 3-cleft; spikelets narrow, terete or nearly so, few–many-flowered, the scales closely appressed and the broad wings of the jointed rhachis enclosing the triangular achene.

Spikelets 1–4-flowered, subterete, usually in dense heads; scales oppressed, several-nerved, the lower empty and often persistent after the fall of the rest of the spikelet; joints of the rhachis winged, enclosing the triangular achene.