68 BOTANY. 



(Phleum), Meadow-grass {Poa), Cock's-foot-grass {Dactylis), Sweet- 

 vernal- grass {AnthoxantJmm), Fescue {Festiica), Dog's-tail-grass {Cyno- 

 siirus), &c. The grains of many other grasses are used for food. 

 Zizania aquatica supplies a kind of rice, in the North-western States ; 

 Setaria germanica yields Gei'man millet ; Panicum miliaceum gives a 

 kind of millet in India, and Aiulropog-on sorghum is known as Durra, 

 an Indian grain. Phalar'is canariensis is the source of the common 

 canary-seed. The cereal grains have been so extensively distributed by 

 man, that all traces of their native country are lost. They seem to be in 

 many instances examples of permanent varieties or races kept up by 

 cultivation. Their grain, or caryopsis, contains a large amount of starch 

 and gluten. Their grasses used for fodder in some parts of the world 

 attain a large size, such as Anthistiria australis, the Kangaroo-grass 

 of New Holland, Tripsaciim dactyloides, the Gama-grass of Mexico, and 

 Dactylls ccespitusa, the Tussac-grass of the Falkland Islands. Some of 

 these are five or six feet in height, and are, nevertheless, sufficiently 

 delicate to be used as food for animals. The Tussac has been introduced 

 into England, and thrives Avell in peaty soils within the influence of 

 the sea-spray. It promises to be a valuable grass in the Hebrides of 

 Scotland. 



Sugar is a valuable product obtained from many grasses. It has been 

 produced in Italy from ^Sorghum saccharatiim, Sweet Sorgho ; in China, 

 from iSaccharum sinense ; in Brazil, from Gyneriuin saccharoides ; in the 

 West Indies, from Saccharmn violaceiun ; and in many other parts of the 

 world, from S. officinarum. The two last are commonly known as sugar- 

 cane, and they are generally considered as varieties of a single species, 

 Saccharum officinarum, which is now Avidely spread over various parts of 

 the world. Six or eight pounds of the saccharine juice of the plant furnish 

 one pound of raw sugar. The recent discoveries of Melsens and others, 

 however, promise a much greater yield than this. 



Trihe 1. AndropogonecE. Spikelets bifloral : inferior flowers always incom- 

 plete. Palese more delicate than the glumes, most often transparent. 



This tribe is of great interest from containing the genus Saccharum, or 

 sugar-cane, the principal species of which, S. officinale, is shown on 

 pi. 55, ßg. 8. Here the figures, a to c, represent the entire plant in various 

 stages ] d to g, pieces of the stalk ; and h, the flowers ; Ih, three spikelets 

 with a single flower below. Species of Sorghum furnish broom corn {>S. 

 saccharatuni), guinea corn (»S*. cernunm), and Indian millet (*S'. vulgare). 



Trihe 2. RotboslliacecB. Spikelets, uni- or bi-floral, rarely trifloral, lodged 

 in an excavation of the axis or rachis, sometimes solitary, sometimes 

 geminate ; the one pedicillate, the other subsessile. One flower in all the 

 bifloral spikelets (either superior or inferior) very often incomplete. 

 Glumes one or two, occasionally none, most generally coriaceous. Paleae 

 membranaceous, rarely bearded. Styles one or two, sometimes very short, or 

 none. Rachis more generally articulated. 



Tribe 3. Hordeacece. Spikelets, several- (rarely one-) flowered, sessile on 

 opposite sides of a zig-zag, channelled and toothed, sometimes jointed 



