498 



ILLUSTRATIONS OF THE NATURAL ORDERS. 



hilum (Fig. 120-128,622-624). — ^^. Agrostis, Phleum, Poa, 

 Festuca, which are the principal meadow and pasture grasses : Ory- 

 za (Rice), Zea (Maize), Avena (the Oat), Triticum (AVheat), Secale 

 (Rye), Hordeum (Barley), are the chief cereal plants, cultivated for 

 their farinaceous seeds. This universally diffused order is one of 

 the largest of the vegetable kingdom, and doubtless the most impor- 

 tant ; the floury albumen of the seeds and the nutritious herbage 

 constituting the chief support of man and the herbivorous animals. 

 No unwholesome properties are known in the family except in the 

 grain of Darnel, which is deleterious. Ergot, or Spurred Rye, is 

 no exception, being a morbid growth, caused by a parasitic fungus. 

 The stems of grasses frequently contain sugar in considerable quan- 

 tity (especially when they are solid) ; as in Maize, the sweet variety 

 of Sorghum vulgare, or Broom-Corn, and in Sugar-Cane (Saccharum 

 officinarum), which affords the principal supply of this article. 



1274 1275 



1276 1277 1278 



1273 



1266 



1268 



1270 



i.rj 



FIG. 1266. One-flowered spikelet or locusta of Alopecurus, -with the glumes separated. 

 1267. Same, -with the glumes removed : an awn on the back of the outer palea. 1268. One- 

 flowered spikelet of an Agrostis. 1269. Pistil of a Grass, showing the two feathery stigmas, 

 and the two hypogynous scales or squamulae, larger than usual (representing the perianth). 

 1270. Two-flowered spikelet of an Avena ; with the glumes spreading. 1271. One of the flow- 

 ers with its paleae ; the exterior pointed, with two bristles or cu.«ps at the apex, and with a 

 bent awn on the back. 1272. Many-flowered spikelet of Glyceria fluitans. 1273. An enlarged 

 separate flower of the same, seen from witliin, showing the inner palese, &c. 1274. The fruit 

 (caryopsis) of the Wheat, with an oblique section through the integuments of the embryo, 

 which is exterior to the albumen. 1275. Detached magnified embryo : a. the imperfect cotyle- 

 don ; 6, the first leaf of the plumule ; c, the second leaf of the plumule ; d, the radicle. 1276. 

 The caryopsis of Ilordeum (Barley;. 1277. A cross-section. 1278. A vertical section, show- 

 ing the external embryo at the base. 1279. Magnified detached embryo, with its broad cotyle- 

 don and the plumule, 1280. More magnified vertical section of the game : a, the plumule ; b, 

 the radicle. 



