178 



MONOCOTYLEDONS 



to twist so that the true anterior part of the flower occupies 

 a posterior position. Thus the labellum is in reality a 

 median posterior perianth-leaf, and all the other floral-leaves 

 have their true positions reversed in the same manner. The 

 flower consists thus of six perianth-leaves, the 

 median posterior being 

 the labellum ; three 

 gynandrous stamens, 

 only one (median an- 

 terior) of which is 

 complete ; a gynsecium 

 composed of three car- 

 pels, syncarpous, with 

 three stigma-lobes, the 

 anterior median lobe of 

 which no longer func- 



Fig. 225. — Fruit of 

 4,' „„ „ „4.;^,„„ U,,*. Orchis inascKla : d= 



tions as a stigma, but subtending bract ; j= 

 is the rostellum (see s^="^s- 

 fig. 224 for further details). The floral formula is P3-I-3 

 Al-1-2 G(3). Fruit (fig. 225) a capsule dehiscing along the 

 dorsal sutures, and allowing the innumerable minute seeds 

 to be dispersed by the wind. 



[In place of Orchis mascula, other British species of Orchis 

 may be selected for examination, and the various points 

 described above will be easily seen.] 



Fig. 224. — Floral diagram 

 of Orchis, 



AEACE.S (Arum Family) 



Smooth herbs with leaves which are often broad and net- 

 veined. Inflorescence a spadix with a spathe ; no bracts 

 subtending the separa,te flowers; no prophylls in the inflores- 

 cence. Flowers small, inconspicuous. Perianth small or 

 absent. Fruit, a berry. 



Type : THE CUCKOO PINT (Arum maculaUcm). 



Vegetative characters. — Herb with a corm. The leaves 

 are radical, each possessing a basal sheath, a petiole, and a 

 net-veined spotted lamina shaped almost like an arrow-head. 

 Inflorescence (fig. 226).- — A large sheathing bract — the spathe 



