DESCRIPTIVE AND SELECTIVE. 247 



rockery, where they will thrive in loamy soil on a sunny 

 site. They can be raised from seed sown in a frame 

 in spring, and subsequently increased by division in 

 spring if desired. Luciliae is a pretty little Alpine, 

 with glaucous leaves and blue flowers in summer. 

 Verna is better known. This flowers in spring, and 

 has blue flowers with a white centre. There is a white 

 variety of it called alha. 



ONOBRYCHIS. —TUs is a genus of the Pea order 

 of very little use for the rockery, and yet containing a 

 variety which, as one of the coloured plates shows, is 

 a good Alpine plant. This is the mountain form of 

 the common Sainfoin, 0. sativus montana. It is of 

 low growth, and has purplish rose flowers. The 

 Sainfoins thrive in loamy soil, and are easily raised 

 from seed sown in spring. 



ONONIS (Rest Harrow).— The British Rest 

 Harrow, 0. arvensis, with pink flowers in summer, 

 and its white variety alba, are well suited to the rockery. 

 They are of tufty habit, grow in ordinary soil, if it is 

 not wet and heavy, and are easily propagated by 

 division in spring. Rotundi folia makes a small neat 

 bush about eighteen inches high and produces rosy 

 flowers in summer. 



ONOSMA TAURICUM (Golden Drop).— An 

 exquisitely beautiful rock plant, with grey-green tufts 

 of foHage a few inches high, and sprays of fragrant 

 yellow flowers. This grows with me on the face of a 

 rock wall in poor chalky soil, and seems quite at home. 

 On a wet place it is better for protection with a square 

 of glass during winter. It is propagated by seed, sown 



