TRIANDRIA, DIGYNIA. 
62. A VENA, Gen. pi. 122. Gramineas.) 
69 
Calix 2-valved, 2, 3, or many-flowered. Co- 
rollay exterior valve lanceolate, some tv hat te- 
rete, furnished with a dorsal awn. Awn ge- 
niculate, and contorted. Seed for the 
most part invested by the corolla.” Schrader. 
(Glumes of the calix membranaceous, re- 
sembling follicles.) NutU 
1. A. culm 3 feet high, jointed, joints oblong smoth. eiatior. 
Leaves lanceolate. Branches of the panicle soli- 
tary and ternate divided. CaL 2-flowered, 2- 
valved, valves unequal, with one flower awnless, 
the other awned. Cor* glume 2-valved, the awn 
bearded at the base. Stam. 3 with yellow an- 
thers. Pist. 2 white plumose. MuhL 
Found frequently in cultivated fields, interspersed with 
grass and grain. Introduced with grass-seeds from Europe, 
but now naturalized. Perennial. June. 
2. A. culm half a foot high jointed, joints smooth, paiustm. 
Leaves linear-lanceolate nerved smooth. Sheath 
striate smooth. Ligula small bearded. Panicle 
narrow ; branches unequal 4 — 6, 1 -flowered and 
many-flowered smooth. Cal* 2-valved acute 
marginated 2»flowered, one flower sessile, the 
other pedicellated, the pedicel pubescent. Cor* 
2-valved, acuminated in the sessile flowers; the 
awn of the pedicellated flowers oblique at the 
I apex. MuhL 
Aira pallens. Muhl. 
A. Pennsylvanica. Sprengel. 
] This beautiful grass occurs with and without awns. The 
j aristated variety is most common. In Jersey, in damp woods 
I and moist low grounds, frequent . Also occurs on this side 
I of the river, but less often. Perennial. May. 
