734 



BOTANY 



PART II 



spikelets one-flowered, in groups of three ; in the sub-species H. hexastichum 

 and H. tetrastichum all the rows of spikelets are fertile, in H. distichum only the 

 middle row. Oat, Avena sativa. Maize, Zea mais. The above are all cultivated 

 in temperate climates, the Maize largely in America, the others also in Western 

 Asia and the south-east of Europe. In the wild state only Triticum monococcum, 

 var. aegilopodioides (from which Tr. monococcum is derived), Triticum dicoccoides 

 as the original form of Wheat, Secale montanum, and Hordeum spontaneum (allied 

 to H. distichum) are known. In these wild forms the spikelets fall from the 

 rachis at maturity, a character that would be unsuitable in cultivated forms. 



The most important tropical food-plant of the order is Rice, Oryza sativa (Fig. 

 817), which is largely cultivated to the limits of the warmer temperate regions, 

 and, when sufficient moisture is available, yields an enormous harvest (Fig. 818). 

 In Africa several varieties of Millet, Andropogon Sorghum, are cultivated, and it 



IG. 814. Part of median longitudinal section of a grain of Wheat, showing embryo and scutellum 

 (sc) ; vs, vascular bundle of scutellum ; ce, its columnar epithelium ; I', its ligule ; c, sheathing 

 part of the cotyledon ; pv, vegetative cone of stem ; hp, hypocotyl ; I, epiblast ; r, radicle ; 

 d, root-sheath ; m, micropyle ; p, funiculus ; vp, its vascular bundle ; /, lateral wall of groove 

 cp, pericarp, (x 14.) (After STRASBURGER.) 



forms the most important cereal for that continent. Panicum miliaceum and 

 P. italicum, of Asiatic origin, are still cultivated, though to a diminished extent, 

 in the Mediterranean region. The Sugar-cane, Saccharum officinarum, is another 

 important food-plant ; it is a perennial, growing more than six feet high, and 

 occurs in tropical Asia. The sugar-cane is cultivated in all tropical countries, 

 and cane-sugar is obtained from the sap expressed from the solid stem. 



Among the most important of our meadow-grasses may be mentioned 

 Agrostis alba, Alopecurus pratensis, Anthoxanthum odoratum, Arrhenatherum 

 elatius, Avena flavescens, A. pubescens, jBriza media, Dactylis glomerata, Holcus 

 lanatus, Lolium perenne, Phleum pratense, Poa pratensis, and species of Aira, 

 Bromus, Calamagrostis, Festuca, Melica, etc. The tropical species of Bambusa, 

 which grow to the height of trees, are utilised in many ways ; from the stems 

 are constructed houses, walls, flooring, ladders, bridges, cordage, water- vessels, 

 cooking utensils, water-pipes, etc., and the plant is indispensable in the countries 

 in which it occurs. 



