28 CLASS III. ORDER III. 



Common foxtail grass is well marked by the upper sheaths, 

 which appear as if inflated. Culm two or three feet high. 

 Spike lobed. Calyx acute, villous. Corolla nearly equal to the 

 calyx. Awn twisted. — Fields, &c. — May. 



An early, excellent grass, probably introduced. 



Alopecurus geniculatus. L. Floating Foxtail grass. 



Culm ascending, bent at the joints ; spike somewhat 

 compound, cyhndrical ; glumes obtuse, hairy. Sin. 



Stems of various lengths, ascending, forming knees or angles 

 at the joints, and rooting from the lower ones, when the plants 

 grow in the water. Leaves rather smooth and short, their 

 sheaths a little swelling. Spike cylindrical, obtuse, divisible 

 into lobes. Glumes of the calix obtuse, fringed wiih long hairs. 

 Corolla awned at base. — Ponds and ditches. — July. — Perennial. 



28. TRICHODIUM. 

 Triciiodium laxiflorum. Mich. Thin grass. 



Culms erect; leaves narrow, short; sheaths some- 

 what rough. Pers. 



This grass is readily known by its very thin, spreading, capil- 

 lary panicle. Stem erect, smooth, slender. Leaves short, gla- 

 brous, on roughish sheaths. Panicle consisting of very long, 

 straight, rough branches, of a purplish color, hardly larger than 

 hairs, and very flexible. These are given off" in half whorls, 

 and are repeatedly subdivided into three or four branchlets at a 

 time. Flowers minute, scattered at the ends of the branches. 

 Glumes lanceolate, acute. — Roadsides. — July. — Perennial. 



29. MUHLENBERGIA. 

 § Subgenus Brachtelttrum. U]}p€r valve of the corolla with 

 a clavate rudiment at base. 



MuHLENBERGiA ERECTA. Sckrch. Ercct Muhlcnbergiu. 

 Culm erect, simple ; leaves pubescent; panicle lax ; 

 calyx with a long awn. 



Syn. Brachyelttrum aristatum. Beauv. 



DiLEPTRUM ARISTOSUM. Mx. 



