1876 



A TEXTBOOK OF THEORETICAL BOTANY 



Fig. 1783. — Hottouia. Flowers in longitudinal section to illustrate pollination. 

 The flowers are heteromorphic with regard to stamen length. A, Short 

 stamens. B, Long stamens. {After Kmith.) 



The tribe Cyclamineae contains the single genus Cyclamen (Fig. 1784) 

 with sixteen species, which occur chiefly in the Mediterranean region. 

 There is a stout corm or tuber originating from the hypocotyl, from which 



Fig. 1784. — Cyclamen neapoUtanum. Flowers. 



the leaves and flower stalks arise annually. The flowers are pendulous and 

 the petals reflexed. The pollination mechanism (Fig. 1785) is interesting, 

 and recalls that in Erica. At first the flowers are entomophilous, the anthers 

 clasping the style, and the pollen is covered with a sticky oil. Later this 

 pollen becomes powdery and the angle at which the flower hangs becomes 

 more acute, so that the pollen grains fall on the style when the flower is 

 shaken by the wind. After pollination the stalk usually coils up spirally, 

 drawing the ripening fruit into the soil. (See Fig. 143 1.) In C persiciim the 

 stalk bends over and actually forces the fruit into the ground. Cleistogamic 

 flowers are sometimes produced in this genus. 



