212 ALPINE FLOWERS AND ROCK GARDENS. 



be grown on the rockery in a sheltered place, as it is 

 not hardy. Both have yellow flowers in summer. 



COTYLEDON. — Under this genus of succulents 

 the botanical authorities have now classed Echeverias 

 and Pachyphytums. They are not important to the 

 rock gardener, although the British Wall Navelwort, 

 C. umbilicus y is sometimes grown. The Echeverias are 

 useful plants, but they are more in demand by the 

 bedder-out than the rock-gardener, being used a good 

 deal for planting the raised edges of flower beds. 

 C. umbilicus grows about six inches high, and bears 

 yellow flowers in June. 



CROCUS, see Chapter V. 



CYANANTHUS.—A small genus, of which two 

 species, incanus and lobatus, stand out as the most 

 prominent. The former has Hght blue flowers with a 

 white throat, the latter purpHsh blue blossoms. They 

 are dwarf Himalayan plants, which bloom in August, 

 and enjoy a peaty soil with plenty of grit in it. They 

 love sun. Propagation may be effected by seed, 

 sown in spring, or by cuttings made of the young shoots 

 in spring. Both should have the protection of a 

 frame. 



CYCLAMEN. — Those who only know the various 

 forms of the tender Persian CyclaAen, which is grown 

 by florists into such beautiful specimens for warm 

 greenhouse and conservatory decoration in winter, 

 exclaim in mingled surprise and pleasure when they 

 see a happy colony of hardy Cyclamens, such as the 

 species Coum, Europaeum, Neapolitanum and Vernum. 

 They are attractive both in foliage and bloom. 



