CLASSIFICATION OF ANGIOSPERMS. 



225 



A. CLASS MONOCOTYLEDONS. 



The Monocotyledons are mainly distinguished by having (i) 

 leaves which are parallel (closed) veined, the margins being for 

 the most part entire; (2) the parts of the flower in five circles of 

 three divisions each (Fig. 124) ; (3) a stem with no distinction of 

 pith, wood and bark, but having closed collateral bundles scat- 

 tered through the parenchymatous tissue of the stele (Fig. 114) ; 

 and (4) an embryo with one cotyledon. 



Pig. 123. Cultivated white lily {Liliuyn album) showing typical monocotyledonous flowers. 

 I. ORDER GRAMINALES OR GLUMIFLOR.E. 



This order is composed of the two families, grasses (Gram- 

 ineae) and sedges (Cyperacese). The plants are for the most part 

 annual or perennial herbs with fibrous roots or long rhizomes 

 and slender, usually simple, overground stems (culms). The 

 flowers are small, arranged in spikes or spikelets and are wind- 

 pollinated. Each spike is subtended by one or two bracts known 

 as glumes or scales. The ovary is i-locular and i-seeded and 

 the stigmas are large, hairy or plumose (Figs. 79, F, G ; 125, D). 



a. GRAMINE^ OR GRASS FAMILY.— The culms are 

 mostly hollow ; the leaves are slender and sheathing, usually split 



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