682 



GRAPTOPHYLLUM 



elliptic, acuminate, irregularly marked with yellow along 

 the midrib: fis. crimson, in axillarv whorls; corolla pu- 

 bescent. Habitat'! B.R. 15:1227. 'Lowe 4.^;. iB.M. 1S70 

 shows a variety with reddish brown coloring). 



6BASS (Oraminea;). Annual or perennial herbs 

 (some bamboos woody), mostly tufted or decumbent, 

 rarely climbing, often creeping and rooting at the base. 

 True roots fibrous. Stems (culms) simple or branching, 

 lis ually hollow (wheat), sometimes solid (maize) between 

 the nodes. Leaves springing from the nodes, alternate, 

 in two vertical rows on the stem; the sheaths closed 



983. Spike of a Grass (rye), containing many flowers. 



when young, but usually split down one side in matur- 

 ing; ligule a thin tongue-like growth at the ape.\ of the 

 sheath ; blade entire, parallel-veined, commonly long 

 and narrow; a 2-keeled membranous prophyllum (or 

 leaf) always standing between each branch and the 

 main axis. Spikelets in panicles, racemes or spikes, 

 usually consisting of 2 (rarely 0, 1, or more than 2) 

 chaffy empty glumes at the base of a short axis (ra- 

 chilla), which supports one or more floral glumes, in the 

 axil of each of which is commonly 1 flower. Flowers 



GRASS 



pi-rfect or imperfect, destitute of true calyx or corolla. 

 Between each floral glume and flower are usually 2 

 (rarely 3) minute hyaline scales (lodicules). Stamens 

 3 (rarely 1, 2 or more than 3); pistil 1: ovary 1-celled, 

 1-ovuled ; styles 2 (rarely 1 or 3), u.sually plumose: 

 fruit (grain or caryopsis) seed-like, often enclosed by 

 the palet and its floral glume. Seed erect, closely cov- 

 ered by the thin pericarp; embryo small, on one side of 

 the base of the endosperm. Figs. 981-981 show the 

 structure of various Gr.nss florets. 



Perennial Gr;is-i., ■ vli ,i. •' -.• . , ;,,.,m,ii1;, limwh for 



numerous m tropica 

 lallv scattered, while i 

 .'1. "the si.cci.-s aiv Ic: 



vast areas. Where : 

 the Grasses grow i 

 Plants of one sectioi 



I he 



E:ich sli. siii , |. .i:~ ,11,1 holds erect the tuinlcr lower 

 ]»ortio!i t'l ; ' li. where it is soft and weak; it 



also |.i'. .1 ^' branches or panicles. Thrifty 



blades ..t < .r:i i ~ SI li III 1,1,. for pasture and lawn elongate 

 from the lower iiid, so that when the tips are cut off 

 the leaves do not cease to elongate, but renew their 

 length. When exposed to sun or dry air, the blades de- 

 velop a thicker epidermis, and, by shrinking of some 

 of the delicate bulliform cells of the upper epidermis, 

 they diminish their surface as they roll their edges in- 

 ward or bring them together, like closing an open book. 

 When the plant is in flower the minute and delicate lodi- 



