PHANEROGAMIA 



549 



placentas (Fig. 550). The fertile stamen is adherent to the style 

 and forms with it the COLUMN or GYNOSTEMIUM ; this projects more or 

 less in the centre of the flower. The labellum, which serves as an 

 alighting place for visiting insects, becomes anterior either by the 

 torsion of the whole flower through 180 (cf. Figs. 550 and 553) or 

 by the flower being bent backwards. 



This order of 6000-10,000 species is primarily divided into Monandrae and 

 n, 



I-'H;. .VVt. o/r/iiy i,iii;tnriri. a. Flower: ". 

 bract ; li, ovary ; <, the outer, and d, the 

 two anterior inner perigone leaves : >. 

 labellum with the spur/; g, gynostemium. 



b, Flower after removal of all of the peri- 

 gone leaves with exception of the upper 

 part of the labellum : h, stigmai; I, rostel- 

 him ; fc, tooth-like prolongation of the 

 rostellum ; in, anther ; u, connective ; o, 

 pollininm ; </, viscid disc ; p, staminodium. 



c, A pollinium : r, caudicle ; ,, pollen. 



d, Ovary in transverse section. (After 

 BERd and SCHMIDT.) 



Flo. 554. Vanilla planifnHa (reduced. After BERG 

 and SCHMIDT ; from KNCILER and PRANTL.) A, 

 Labellum and gynostemium ; li, gynostemium 

 from the side ; C, summit of the gynostemium 

 from in front ; Z>, anther ; K, seed. (Magnified.) 



Diaiidrae in which one stamen of the outer whorl or two stamens of the inner whorl 

 are fertile respectively. 



EXAMPLES OF BRITISH GENERA : 1. Monandrae : Orchis, Ophrys, Gymnadenia 

 with tubers -, Epipactis, Cephalanthera, Listcra with branched rhizomes ; Neottia, 

 the Bird's-nest Orchid, Epipogon, Corallorhiza, saprophytie and almost destitute 

 of chlorophyll. 2. Diandrae : Cypripedium, Ladies' Slipper. 



Orchis militaris which is represented in Fig. 555 will serve as an example for 

 more detailed consideration. At the period of flowering a pair of fleshy tubers 

 will be found at the base of the plant, both of which are covered with root hairs. 

 The large or brown tuber of more spongy texture continues above into the stem 



