GRAMINE^E. (GRASS FAMILY.) 567 



26. DIAKRIIENA, Eaf. DIARRHZXA. 



Spikelets several- flowered, smooth and shining, one or two of the uppermost 

 flowers sterile. Glumes ovate, much shorter than tlie flowers, coriaceous ; the 

 lower one much smaller. Lower palea ovate, convex on the back, rigidly cori- 

 aceous, its 3 nerves terminating in a strong and abrupt cuspidate or awl-shaped 

 tip. Squamulse ovate, ciliate. Stamens 2. Grain very large, obliquely ovoid, 

 obtusely pointed, rather longer than the palese, the cartilaginous shining peri- 

 carp not adherent to the seed. A nearly smooth perennial, with running root- 

 stocks, producing simple culms (2 -3 high) with long linear-lanceolate flat 

 leaves towards the base, naked above, bearing a few short-pedicelled spikelets (!' 

 long) in a very simple panicle. (Name composed of Si's, two, and apprjv, man, 

 from the two stamens.) 



1. D. Americana, Bcauv. (Festuca diandra, Michx.) Shaded river- 

 banks and woods, Ohio to Illinois and southward. August. 



27. DACTYL.IS, L. COCK'S-FOOT or ORCHARD GRASS. 



Spikelets several-flowered, crowded in one-sided clusters, forming a branching 

 dense panicle. Glumes and lower palea herbaceous, keeled, awn-pointed, rough- 

 ciliate on the keel ; the 5 nerves of the latter converging into the awn-like point ; 

 the upper glume commonly smaller and thinner. Stamens 3. Grain lance- 

 oblong, acute, free. Perennials: leaves keeled. (Name SoKrvAi's, a finger's 

 breadth, apparently in allusion to the size of the clusters.) 



1. D. GLOMERATA, L. Rough, rather glaucous (3 high) ; leaves broadly 

 linear; branches of tbe panicle naked at the base; spikelets 3-4-flowered. 

 Fields and yards, especially in shade. June. Good for hay. (Nat. from Eu.) 



28. K<ELERIA, Pers. KOJLERIA. 



Spikelets 3-7-flowered, crowded in a dense and narrow spike-like panicle. 

 Glumes and lower palea membranaceous, compressed-keeled, obscurely 3-nerved, 

 barely acute, or the latter often mucronate or bristle-pointed : the former moder- 

 ately unequal, nearly as long as the spikelet. Stamens 3. Grain free. Tufted 

 Grasses (allied to Dactylis and Poa), with simple upright culms ; the sheaths 

 often downy. (Named for Prof. Kohler, an early writer on Grasses.) 



1. K. cristiitsi, Pers. Panicle narrowly spiked, interrupted or lobed at 

 the base ; spikelets 2- 4-flowcred ; lower palea acute or mucronate; leaves flat, 

 the lower sparingly hairy or ciliate. Var. GRAciLis, with a long and narrow 

 spike, the flowers usually barely acute. (K. nitida, Nutt.) Dry hills, Penn. to 

 Illinois, thence northward and westward. (Eu.) 



29. E A T 6 W I A , Raf. (JlEBOt^E A, Kunth, not of Eaddi. ) 



Spikelets usually 2-flowered, and with ah abortive rucument or pedicel, nu- 

 merous in a contracted or slender panicle, very smooth. Glumes somewhat 

 equal in length, but very dissimilar, a little shorter than the flowers ; the lower 

 narrowly linear, keeled, 1-nerved; the upper broadly obovate, folded round the 



