rhachis

One spikelet of each pair sterile and shortly pedicelled, the other fertile, sessile and sunk in the rhachis.

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

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

Perigynium much as in the Montanæ; spike one, staminate above; pistillate flowers few, often remote, usually on a more or less zigzag rhachis; scales prolonged and leaf-like.—Sp.

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 several-flowered, narrow, erect and scattered along the slender rhachis of the long spicate spikes; flowers all perfect or the uppermost staminate.

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