i6 



Introduction to Botany. 



monoecious, or dioecious, and' of several 2-ranked bracts or glumes. 

 Stamens commonly 3, and styles usually 2, but varying from i to 3. 

 ^, Ovary i -celled and i-ovuled. 



4 



Fruit a seedlike grain. See 

 Fig. 341 for a diagrammatic 

 representation of the struc- 

 ture of the flower. 



I. POA. 



Meadow-Grass. 

 Grass. 



Spear 



Diagrams of a typical grass flower, i, a spike- 

 let dissected ; a a, empty glumes ; b b, fertile 

 glumes bearing flowers (c c) in their axils ; 

 d, a glume bearing the sterile flower (e) in 

 its axil ; / the palet. 2, a cross diagram of 

 the same spikelet lettered as above \gg, lodi- 

 cules. 3, a single flower ; / palet ; g, lodi- 

 cule. In part after PRANTL. 



(Greek name for grass or fodder.) 



Annuals or perennials, 

 leaves flat or convolute. 

 Spikelets flattened, ovate, or 

 lance-ovate, 2-6-flowered, in 

 more or less open panicles. 

 Flowers usually perfect, rarely 

 dioecious. The two lower 

 glumes empty, i-3-nerved ; 

 the glumes next the flower 

 longer, and usually with cob- 

 webby hairs at the base, 5- 

 nerved ; palets (see Fig. 341 ) 

 shorter than the glumes, and 

 2-nerved or 2-keeled. 



Poa pratensis, L. (L., pra- 

 tensis, growing in meadows, from 

 pratum, a meadow.) KENTUCKY 

 BLUE GRASS. Smooth, slender 

 stems springing from runningroot- 



stocks; sheaths sometimes longer than the internodes; ligules short and blunt; 



spikelets nearly sessile, 3~5-flowered; upper glumes hairy on the margins and 



keel. Commonly planted for lawns, meadows, etc. 



II. TRIPS ACUM. Gama Grass. Sesame Grass. 



(Gr., tribo, to rub, in allusion to the polished spikes.) 



Stems solid, stout and tall, from thick, creeping rootstocks. Leaves broad and 

 flat. Monoecious spikelets in jointed unilateral spikes ; staminate spikelets in the 

 upper part of the spike, and the pistillate below; staminate spikelets in pairs, 

 2-flowered ; pistillate spikelets with i perfect flower. 



