GRASSES 



GRASSES 



373 



sativa, Linn. Oat. (Fig. 542.) An annual with 

 nodding spikelets and many-nerved glumes, the 

 awns of the persistent lem- 

 mas straight or wanting. A 

 common grain thought by 

 many to have originated 

 from the wild oat (A. fatua, 

 Linn., Pig. 543), which differs 

 in having a geniculate and 

 twisted awn, and a deciduous 

 lemma more or less covered 

 with red- brown hairs. The 

 wild oat is abundantly intro- 

 duced on the Pacific coast. 

 A variety (A. fatua gla- 

 brata, Peterm.) is cut for 

 hay in Washington, and 

 this and an allied species 

 {A. barbata, Brot.) are used 

 for pasturage in Cali- 

 fornia. [See Oats.'] 



22. Dactylis 

 (Greek, finger). A 

 genus of grasses com- 

 prising one species or 

 several closely allied species, 

 native in the northern part of 

 the Old World. Spikelets three- 

 to five-flowered, in dense fasci- 

 cles, these forming a glomerate 

 panicle, spreading in flower but 

 contracted in fruit. Glumes one- 

 to three-nerved, the lemma five- 

 nerved. 



glomerata, Linn. Orchard- 

 grass. (Fig. 544.) Commonly 

 cultivated in the northern states 

 for forage and extensively es- 

 caped in waste places. It is of 

 considerable importance in Ken- 

 tucky, southern Indiana, Ten- 

 nessee, North Carolina, western 

 Virginia, West Virginia and 

 Maryland. 



23. Cynosurus (Greek, dog's- 

 tail). A genus of four or five 

 species of grasses found in the 

 north temperate regions of the 

 Old World. Spikelets of two 

 forms in small fascicles, these 

 forming a dense, spike-like pan- 

 icle ; terminal spikelets of the 

 fascicles two- to four-flowered, 

 perfect, the lower spikelet 

 sterile, consisting of many 

 linear one-nerved glumes. 



eristatus, Linn. Crested Dog's- 

 tail. (Fig. 545.) A perennial 

 grass, one to two feet high, with 

 fine and chiefly radical leaves. 

 Occasionally sown in grass mix- 

 tures but without much forage value. 



24. Poa (Greek, for fodder). A genus of about 

 125 species of grasses, chiefly in the cooler regions 

 of both hemispheres. Spikelets two- to six-flow- 



Flg. S49. Blue-grass 

 or June-grass (Poa 

 pratensis). 



ered, the uppermost flower more or less imperfect ; 

 glumes one- to three-nerved, keeled ; lemma keeled, 

 five-nerved, awnless. Inflorescence a more or less 

 spreading panicle. Annuals or perennials. 



arachnifera, Torr. Texas Blue-grass. (Pig. 546.) 

 A dioecious perennial grass with running rootstocks. 

 The staminate and pistillate panicles are distinctly 

 different in appearance, owing to the fact that the 

 lemmas of the staminate spikelets are smooth while 

 those of the pistillate spikelets are densely long 

 woolly, which character at once distinguishes this 

 species. 



eompressa, Linn. Canada Blue-grass, (f'ig. 547.) 

 A perennial with scattered, flattened stems, six to 

 twenty inches high, from creeping rootstocks which 

 form a strong turf. Panicle comparatively small 

 and narrow. Because of the characteristic shape of 

 the stem it is called flat-stem in the middle Alle- 

 ghany region. In New England and in some other 

 localities it is known as blue-grass, but this name 

 should be restricted to Poa pratensis. It is also 

 sometimes called wire -grass. The foliage has 

 a peculiar blue -green color. It is a native of 

 Europe and of the northern part of America. 



nemoralis, Linn. Wood Meadow-grass. (Pig. 548). 

 A tall perennial (one to three feet) with open spread- 

 ing panicle, four to six inches long ; spikelets 

 mostly two- to three-flowered, lemma webby at base, 

 keel and marginal nerves pubescent, intermediate 

 nerves glabrous and obscure ; ligule very short. 

 This European species is occa- 

 sionally cultivated as a meadow 

 grass or in mixtures, and has 

 escaped in the northeastern 

 states. It is adapted to shaded 

 situations. Probably not na- 

 tive. 



Fig. 550. Detail of blue-grass 

 flower iPoa pratensis). 1, 

 spikelet; 2, floret opened; 

 fl, florets; g, glumes; pd, 

 pedicel; 8t, stamen; a, 

 anthers; f, filaments; s, 

 stigmas; J), paleaj Z, lemma; 

 0, ovary; r, rachilla. 



Fig. 551. Kentucky 

 blue-grass or June- 

 grass (Foa praten- 

 sis). 



pratensis, Linn. Kentucky Blue-grass. (Figs. 

 549-551.) A perennial grass growing in tufts, but 

 producing abundant rootstocks by which it soon 

 forms a flrm sod. Panicles spreading but not dif- 

 fuse, two to flve inches long. Spikelets mostly 

 three- to five-flowered ; lemma much as in the pre- 

 ceding, but the intermediate nerves more promi- 

 nent. A valuable grass, native in the northern 

 part of both hemispheres and widely cultivated for 

 pasture and lawns. It does not thrive in the South. 



