4S0 



BOTANY 



filament. The ovary has two, rarely three, branching stigmas situated 

 either directly upon the ovary itself, or borne on a short style (Fig. 

 421, B). The pericarp is traversed by a longitudinal groove; it is 

 leathery, and assumes the functions usually performed by the seed- 

 coat, which is thin and adherent to it. In many cases (e.g. in most 

 species of Barley) the pericarp and paleae also adhere. On germina- 

 tion a shield-like appendage of the cotyledon, the scutellum, remains 

 within the seed and absorbs the endosperm (Fig. 422). 



Sub-Families (after Hackel) and Representative Geneea. — (1) Maydeae, 

 Zea. (2) Andropogoneae, Saccharum. (3) Paniceae, Panicum, Setaria. (4) Oryzeae, 



Oryza. (5) Phalarideae, Anthoxan- 

 thum. (6) Agrostideae, spikelets 

 stalked, bearing one flower and two 

 glumes ; PMeum and Alopeeurus, 

 with, spikelets aggregated in spike- 

 like inflorescences ; Agrostis, with 

 paniculate inflorescences, inferior 

 paleae, usually prolonged into an 

 awn ; Calamagrostis, with inferior 

 paleae, hairy and awned. (7) Ave- 

 neae, spikelets two-flowered, inferior 

 paleae shorter than the glumes ; awn 

 kneed. Avena, spikelets in panicles, 

 fruit hairy ; Aira ; Eolcus. (8) 

 Chlorideae, Cynodon. (9) Festuceae, 

 spikelets two- to four - flowered, in 

 panicles or racemes ; inferior paleae 

 longer than the glumes, with or 

 without awns ; Phragmites, Melica, 

 -Part of median longitudinal section of a Brial/t D ac tylis, Poa, Bromus. (10) 



Hordeae, spikelets one or several 



, micropyle ; p, funiculus ; vp, its vascular bundle ; 

 /, lateral wall of groove. ( x 14.) 



Fig. 42: 



grain of wheat, showing embryo and scutellum 

 (sc) ; vs, vascular bundle of scutellum ; cr, its 

 cylinder epithelium; V, its ligule ; c, sheathing flowered, situated in two rows, in 

 part of the cotyledon ; pa, vegetative cone of stem ; depressions of the main floral axis, 

 hp, hypocotyl ; I, ligule ; r, radicle ; cl, root-sheath ; anc [ forming a compound spike. 



Lolium, Secale, spikelets solitary in 

 the depressions of the axis, glumes 

 awl-shaped and uninerved ; Triticum, similar to Secale, but with ovate, three- to 

 many-nerved glumes. Sordeum bears several spikelets on each segment of the axis, 

 spikelets single-flowered. (11) Bambuseae, shrubs and trees ; Bambusa. 



Geographical Distribution. — Like the Cyperaceae, the Gramineae are widely 

 distributed over the whole world. They appear in the most varied situations, in 

 particular in meadows and fields, of which they form the principal vegetation. 

 Among the most important meadow-grasses the following may be mentioned : Poa 

 pratensis, Common Meadow Grass or Kentucky Blue Grass ; Agrostis vulgaris, Red- 

 top ; Alopeeurus pratensis, Meadow Foxtail ; PMeum pratense, Timothy ; Dactylis 

 glomerata, Orchard Grass ; Briza media, Quaking Grass ; Anthoxanthum odoratum, 

 Sweet Vernal ; Lolium perenne, Rye Grass ; Holcus lanatus, Velvet Grass ; Arrhena- 

 therum elatius, False Oat Grass ; Avena pubeseens and A. flavescens, the Yellow Oat 

 Grass, etc. The arborescent grasses of the genus Bambusa and its allies form ex- 

 tensive groves in the Tropics, or the smaller forms grow in the shade of the primitive 



