GROUP V. AXGIOSPERXLE ; MONOCOTYLEDOXES. 



505 



Most of the indigenous species have underground rhizomes or 

 tubers. In the latter case, two tubers are usually present : the 



Fis. 317. Tubers (A) of Orchis Morio; B of Gymnndenia Conopuca : s the peduncle; 1 this 

 year's tuber ; 2 next year'* tuber; fc the bud ; w and tc' roots (nat. size). 



older one, which, at the time of flowering, becomes flaccid (Fig. 317 



A and S, 1), throws up the flowering scape (s) or, in young plants, 



a short underground stem which produces only leaves above ground. 



At the upper end of this tuber another much firmer tuber is formed 



(Fig. 317, 2), bearing at its apex the bud of the next years stem (A'). 



The tuber is to be regarded as a 



lateral bud which coalesces with its 



first root (or more than one, Fig. 



3175) and then increases in bulk: 



the lower end of an undivided tuber, 



as well as the ends of palmate tubers, 



has, in the young state at least, the 



same structure as the apex of a true 



root. 



The genera of Orchid aceae are so nu- 

 merous and so diverse that it is impossi- 

 ble to give more than a summary of 

 those which are British. 



DIANDR.E : two fertile stamens, belong- 

 ing to the inner whorl: all three lobes 

 of the stigma are susceptible of pollina- 



tion: pollen-grains cohering but slightly. 

 -c, ., 7, . ,.. f. j- 



Fam. 1. tVr^te. C W r,^,. 



Calceolus, the Lady s Slipper, now very 

 rare, occurs in woods in the north of 



FIG. 318. Flower of Cypripedium 

 Calceolus .- ji p the leaves of the peri- 



*"& "" ** c l Rwav - * 8ide 

 view. B Back view. C Front view; 

 , ovftry; ^ gjno8tmilim ; . . the 



two fertile 8tamen9 . staminode; n 

 btigma. (After Sachs.) 



