478 



GRAMINE^. TRUE GRASSES 



The leaf-Made is generally long, narrow, and flat, but in 

 grasses growing in dry places it is often folded and appears 

 almost cylindrical (Fig. 183). 



The first leaf of the embryo and those upon the underground 

 rhizomes are almost always modified structures representing leaf- 

 sheaths the blades of which remain undeveloped or rudimentary. 

 It is important to notice the arrangement of the leaves in the 

 bud as it often affords a ready means of 

 distinguishing nearly - allied species of 

 grasses. Most frequently the leaves are 

 rolled up from one side in a spiral form, 

 and the young shoot appears round (Fig. 

 191), but in several grasses they are 

 simply folded down the middle, the shoot 

 then appearing flattened (Fig. 188). 



At the point where the 

 blade joins the sheath the 

 inside of the latter often 

 protrudes as a tongue-like 

 membranous structure (/ 

 Fig. 149), termed the ligule. 

 The latter varies much in 

 length in different species. 

 Near the ligule the sides of 

 the leaf sometimes terminate 

 in claw-like projections which partially or entirely encircle the 

 stem as in Figs. 154 and 189. 



Inflorescence. — In the figure of annual meadow-grass (Fig. 

 149), the branched upper part popularly termed the 'flower' 

 is a complex inflorescence bearing flowers which are very small 

 and completely hidden from view. The parts c are termed 

 spikelets, and it is within these that the flowers are enclosed. 



A single spikelet is illustrated in Fig. 150. On examination 

 it is seen to consist of an axis r, the rachilla, upon which is 



3 4 . 



Fig. 150. — I. Spikelet from grass of Fig. 149. 



2. The same slightly opened to show separate 

 glumes and florets, a Empty glume ;yfiowering 

 glumeof second floret; rrachilla or axis of spikelet. 



3. Single floret of 2. y Flowering glume \p palea ; 

 o ovary of gynaecium ; r piece of rachilla. 



4. The flower. I Lodicules ; o ovary ; j stigma ; 

 a stamen. 



