24:6 



PLANT STRUCTUEES 



In the general lily alliance, composed of eight or nine 

 families, there are more than four thousand species, repre- 

 senting about one fifth of all the Monocotyledons, and they 

 are distributed everywhere. They are almost all terrestrial 

 herbs, and are prominently geophilous (" earth-lovers ") 



that is, they develop 

 bulbs, rootstocks, etc., 

 which enable them to 

 disappear from above 

 the surface during un- 

 favorable conditions 

 (cold or drought), and 

 then to reappear rap- 

 idly upon the return 

 of favorable conditions 

 (Figs. 227, 228, 231, 

 233). 



In the regular lily 

 family (LiliacecB) the 

 flowers are hypogy- 

 nous and actinomor- 

 phic (Fig. 231), the 

 six perianth parts are 

 mostly alike and some- 

 times sympetalous (as 

 in the lily-of-the-val- 

 ley, hyacinth, easter 

 lily) (Figs. 201, 229), 

 the stamens are usu- 

 ally six (two sets), 



and the three carpels are syncarpous (Figs. 204, 230). 

 This is a higher combination of floral characters than 

 any of the preceding groups presents. Hypogyny and 

 actinomorphy are low, but a conspicuous perianth, syn- 

 carpy, and occasional sympetaly indicate considerable ad- 

 vancement. 



FIG. 227. Wake-robin (Trillium), showing root- 

 stock, from which two branches arise, each bear- 

 ing a cycle (whorl) of three leaves and a single 

 trimerous flower. After ATKINSON. 



