rhachis

The rhachis or the whole inflorescence and the lower sheaths are sometimes very pubescent.

From The Manual of the Botany of the Northern United States Including the District East of the Mississippi and North of North Carolina and Tennessee by Asa Gray

Perennial; leaves linear, short; spikes 3–7, the lowest partly included in the sheath of the uppermost leaf, the rhachis blunt; spikelets glabrous.—Low or wet grounds, N. J.

From The Manual of the Botany of the Northern United States Including the District East of the Mississippi and North of North Carolina and Tennessee by Asa Gray

Spikelets densely imbricated in two rows on one side of the flat curved rhachis of the solitary terminal spike.

From The Manual of the Botany of the Northern United States Including the District East of the Mississippi and North of North Carolina and Tennessee by Asa Gray

Style 3-cleft; achene triangular; stamens 3; spikelets many-flowered, flattened, the carinate scales decurrent upon the rhachis as scarious wings; spikes in simple or compound umbels.

From The Manual of the Botany of the Northern United States Including the District East of the Mississippi and North of North Carolina and Tennessee by Asa Gray

Spikelets 4–8-flowered, glabrous or nearly so; glumes 3–7-nerved; rhachis glabrous, but rough on the edges; awns when present straight; leaves flat and often roughish or pubescent above.

From The Manual of the Botany of the Northern United States Including the District East of the Mississippi and North of North Carolina and Tennessee by Asa Gray