MONiM'dTVI.KIIoMS ANli T)l('( iT Vl.KIK iNS g^Y 



miirgiii of tlio leaf, but forms a " closed venation/" so that 

 the leaves usually have an even {entire) margin. There 



are some notable exceptions 

 to this character. 



(•1) Cyclic iiowers trim- 

 erous. The "three-parted" 



FrG. 3-33. Twu type?? of leaf venation: ttie figure to the left is from Solomon's seal, 

 a MonocotjOedon, and shows the prineipal veins parallel, the very minute cross 

 veinlets being invisible to the naked eye; that to the right is from a willow, a 

 Dicotyledon, and shows netted veins, the main central vein (midrib) sending out 

 a series of parallel branches, which are connected with one another by a network 

 of veinlets. — After Ettingshausen. 



flowers of cyclic Monocotyledons are C|uite characteristic, 

 but there are some trimerous Dicotyledons. 



Dicotyledons. — (1) Embryo with lateral cotyledons and 

 terminal stem-tip. 



(2) Vascular bundles of stem forming a hollow cylinder 

 (Fig. 334, «•). This means an annual increase in the diam- 



