526 



BOTANY OF THE LIVING PLANT 



Corolla, petals 4, gamopetalous, inferior, globose, with a narrow opening, 

 through which the capitate stigma projects. 



Androecium, stamens 4+4, free, hypogynous, with curved filaments; 

 anthers dehiscing by two distal pores, which face downwards. From the base 

 of each anther two divergent spurs project outwards to the inner surface of 

 the corolla. 



Gynoecium, carpels 4, syncarpous, superior, style elongated, with capitate 

 stigma. Ovary with 4 loculi, ovules minute, numerous, on an enlarged axile 

 placenta. Honey-disc round the base of the hairy ovary. 



Fruit, a loculicidal capsule, from which the minute seeds are shaken by wind. 



FIG. 433. 

 Erica tetralix. I. whole flower from outside. II. flower in section. III. floral diagram. 



Pollination is by bees, which hang on to the pendent flowers. The bee first 

 touches the sticky stigma, depositing pollen it may have brought from another 

 flower ; then inserting the proboscis, it collides with the spurred stamens, 

 shaking out a shower of dry pollen. Thus there is a high probability of cross- 

 pollination, though self-pollination is possible by some falling upon the stigma 

 of the same flower. The gamopetalous corolla with narrow mouth, and the 

 spurred stamens exclude small thieving insects. 



(34) Compare the Bilberry (V actinium myrtillus, L.), in which the floral 

 structure is essentially the same, but the ovary is here inferior. In this genus, 

 and in the Ericaceae generally, there is frequent meristic variation, the flowers 

 being either tetra-merous or penta-merous. 



ORDER : PRIMULALES. 

 Family : PRIMULACEAE. Example : COMMON PRIMROSE. 



(35) The Primrose (Primula vulgaris, Huds.) is a perennial with its stock 

 covered with old leaf-bases, and ending in a rosette of leaves of the current 



