GENERAL BOTANY 



The original distinction between the monocotyledons and the 

 dicotyledons was based upon the number of cotyledons in the 

 embryo, as the names signify, since the monocotyledons were 

 known to have embryos with but one cotyledon, while the 



Parallel} 

 veined 



leaf] 



ISlem *-^/ 



(bundles scattered) ( vascular cylinder} Belted-veined leaf 



*>) 



Flower' 



Floral plan. FloraTplan 

 of three O ffi ve 



'Seed 



Cotyledon-/.] 



'Stem apex. .1 I 

 Hypocotyl-\ I 



Embryo 

 (monocotyledon} 



| Cotyledon- 



Stem apex^ 



-Hypocotyl- 



Enwryo' 

 (dicotyledon) 



Seed 



FIG. 263. Comparison of monocotyledons and dicotyledons 



a, vegetative and reproductive structures of a monocotyledon ; 6, similar structures 



of a dicotyledon 



embryos of dicotyledons had two cotyledons, as in the common 

 beans and peas. The mature plants of the two groups also 

 manifest quite marked distinctions, which apply to the form 

 and venation of the leaves, the structure of the stem, and the 

 numerical plan of the flowers (Fig. 263). 



The leaves of monocotyledons are usually linear with parallel 

 venation, like the leaves of lilies and grasses. The venation is 



