ANGIOSPERM^E 



189 



ble, however, that the two families are not closely re- 

 lated, and the sedges are probably more nearly related 

 to some other group of Monocotyledons, possibly the 

 Rushes (Juncacese) than to the grasses. Whether the 

 simple type of flower found in the grasses and sedges 



nx: 



FIG. 46 (Monocotyledons Liliiflorse). A, a plant of yellow adder-tongue 

 (Erythronium ) , a typical liliaceous plant ; B, the underground thickened 

 stem or bulb, with the simple roots growing from it ; C, the pistil, com- 

 posed of three united carpels; D, diagram showing the arrangement of 

 the parts of the flower ; E, flower of Narcissus, differing from the true 

 lilies in having an "inferior" ovary, o: F, flower of an Iris, a highly 

 specialized flower adapted to insect pollination ; G, cross-section of the 

 stem of Iris, showing the arrangement of the tissues in a typical mono- 

 cotyledonous stem ; vb, the vascular bundles ; H, a flower of the pick- 

 erel-weed (Pontederia) ; the flower is strongly " zygomorphic," i.e. 

 bilaterally symmetrical, and the stamens are in two sets. 



is primitive, or whether it is the result of reduction from 

 a more complex one, must remain for the present unde- 

 cided. 



All of the higher Monocotyledons are distinguished 

 by much more specialized flowers than those found in 

 the forms just considered. This specialization maoi- 



