454 



STRUCTURE AND LIFE HISTORIES 



''seed-leaves," or cotyledons, and on this basis Ray 

 (1628-1705), the noted English botanist, divided his two 

 major groups, flowering herbs (herbcE perfectce) and trees, 



Fig. 338. — Morphology of typical monocotyledonous plant. A^ leaf, 

 parallel- veined; B, portion of stem, showing irregular distribution of vas- 

 cular bundles; C, ground plan of flower (the parts in 3's); D, top view of 

 flower; E, seed, showing monocotyledonous embryo. 



into two sub-groups monocotyledons and dicotyledons} 



These two groups are distinguished by other characters 



^ Plants like Pinus having more than two cotyledons are polycotyledons. 



