526 



BOTANY OF THE LIVING PLANT 



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

 tlirough which the capitate stigma projects. 



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

 anthers dehiscing by two distal pores, which face do\vnwards. From the base 

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

 the coroUa. 



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

 stigma. Ovary with 4 locuH, 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 tetndix. I. whole flower from outride. 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, 

 shaldng out a shower of dry^ pollen. Tlrus there is a high probability of cross- 

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

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

 spurred stamens exclude small thieving insects. 



(34) Compare the Bilberry (Vaccinium myrtilliis, 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 iiieristic variation the flowers 

 being either tetra-merous or penta-merous. 



ORDEiv : PRIMULALES. 



Familv : Primulaceae. Exainplii : Common Primrose. 



(35) The Primrose [Priinnla vulgaris, Pluds.) is a perennial with its stock 

 covered witli old leaf-bases, and ending in a rosette of lea\'es of tlie current 



