318 



BRITISH FLOWERING PLANTS 



function. It is a glandular-pubescent sub -Alpine plant, 

 found in the North of England and Scotland. The 



Fig. 203. Fig. 204. Fig. 205. 



Pig. 203. — Barlsia alpina. Subterranean bud. Nat. size. 

 Fig. 20i. — Cross section through part of this bud. x 60. 

 Fig. 205. — The margin of a bud scale in section, x 200. 



leaves are typical of plants growing in cold, wet regions 

 (see Cerastium alpinum, p. 28). 



B. Odontites. — The flower forms a tube 4-5 mm. 

 long, at the base of which is the honey, while the 



entrance is protected 

 against rain by the four 

 hairy anthers. These lie 

 close together ; but im- 

 mediately below them 

 the filaments of the 

 stamens separate, so as to 

 leave a space (Fig. 206, .e) 

 through which bees can 

 insert their proboscis and 

 thus reach the honey. 

 In doing so they natur- 

 ally dust themselves with 

 pollen, some of which 

 they transfer to the stigma (Figs. 206, 207, st) of the 

 next flower they may visit. In warm and sunny places, 

 where insect visits are numerous, the stigma projects 

 well above the anthers (Fig. 207) ; in cold and shaded 

 places, where insects are comparatively few, it scarcely 

 projects beyond the anthers. 



Fig. 206. Fig. 207. 



Fig. 206. — Bartsia Odontites. Flower with 



short pistil. 

 Fig. 207. — Flower with long pistil. 



e, entrance to flower ; st, stigma. 



