338 FLOWERS OF GARDEN AND GREENHOUSE 



of the European Alps. Introduced 1813. The var. Charmelii does not 

 greatly difFer from this, though regarded by some authors as a distinct 

 species. 



Ph. spicatum (spiked). Stems 1 to 3 feet, ribbed. Leaves heart- 

 shaped. Flowers yellowish, in cylindrical heads ; May and June. Varies 

 white to blue in cultivation. Native. 



Natural Order Ericace^. Genus Erica 



Erica (name classical). A large genus comprising about four hundred 

 species of rigid, much-branched evergreen shrubs. The leaves are small, 

 usually whorled (occasionally alternate or scattered), slender and rigid. The 

 flowers have mostly a nodding habit. Four is the dominating number 

 in this genus, and to a considerable extent throughout the Order. Sepals 

 four. Corolla, bell-shaped, globular, or tubular, f our-lobed, of a persistent 

 character, and secreting honey. Stamens eight, the anthers opening by slits 

 or pores at the edges. Ovary four-celled ; style thread-like, ending in an 

 enlarged four-lobed stigma. The species are natives of Europe, Northern 

 Asia, North Africa, and more especially South Africa. 



Five species of Erica are natives of the British Isles, 

 two of them abundant on heaths generally, two almost 

 restricted to Cornish moors, and the fifth to boggy moors in Mayo and 

 Galway. These are all deserving of a place in gardens of any size. The 

 cultivation of the exotic species appears to have begun in 1658 with the 

 introduction of E. arhorea from Southern Europe, but most of the forms 

 known to gardeners are natives of the Cape of Good Hope, whence they 

 have been brought during the eighteenth and nineteenth centuries. Some 

 of the most popular are hybrids that have been raised in cultivation as 

 the result of experiments in cross-fertilisation between different species. 

 The method by which this is effected naturally between individuals of 

 the same species is exceedingly interesting. The anthers so press to- 

 gether that they form a ring round the style, and the openings for the 

 exit of the pollen are thus kept closed. But if a bee in exploring for 

 honey pushes his long tongue into the mouth of the flower, the ring is 

 broken, the openings of the anthers are exposed, and the pollen falls upon 

 the bees face, just where on visiting a second flower it will be pressed 

 against the more prominent stigmas. In our own E. Tetralix the anthers 

 have each a couple of horns spreading towards the more globular corolla, 



