76 LINAGES. [CHAP. 



the stamens. Hypericum perforatum (the Common 

 Hypericum) is so named from the remarkable pecu- 

 liarity of having the leaves studded by pellucid 

 dots ; and several of the species have the sepals 

 fringed with black or red glands. The flowers 

 belonging to this genus are generally very con- 

 spicuous, both from their bright yellow colour and 

 from their association in clusters. They secrete no 

 honey, but are frequently visited by insects, partly 

 for the sake of the pollen, partly perhaps in a vain 

 search for honey. Under these circumstances, cross- 

 fertilisation must frequently occur, though no doubt 

 the flowers often fertilise themselves. 



LINAGES. 



This order contains two British genera, Linum, and 

 Radiola ; the former is the well-known flax, the latter 

 a minute erect annual, which grows on heaths and 

 sandy places. The genus Linum contains five British 

 species, which differ considerably in the size of their 

 flowers, from the beautiful, blue, common flax, to the 

 minute L. catharticum, the petals of which are but 

 little longer than the calyx, and which yet secretes 

 honey, from five minute glands situated on the outer 

 side, and near the base of the five stamens. It is 

 therefore, in spite of its minute size, frequently visited 

 by insects, though in their absence it is capable of 

 self-impregnation. So far as has been hitherto 

 observed L. usitatissimum, though differing so much 

 from L. catharticum in the size of the flowers, agrees 



