240 ALPINE FLOWERS AND ROCK GARDENS. 



LINUM (Flax). — ^The Linums are useful and 

 popular plants, giving in several cases bright blue flowers. 

 The dwarfer kinds are charming for the rockery, notably 

 Alpinum, which only grows a few inches high, and 

 bears its lovely flowers in July. They are of a rich, 

 intense blue. Gritty loam, with a little peat, suits it, 

 and it may be raised from seed in spring and propa- 

 gated by division between autumn and spring. 

 Arbor eum is a shrub, growing about a foot high and 

 bearing yellow flowers in spring and early summer. 

 It is a handsome little evergreen, but it is not quite 

 hardy and should have a sheltered, warm place . It may 

 be propagated by cuttings in spring, which should be 

 inserted in gritty soil under glass. Flavum is a popular 

 herbaceous species, growing about a foot high and 

 bearing yellow flowers in summer. The treatment 

 advised for Alpinum will suit it. Monogymim is a 

 beautiful New Zealand species, with large white flowers, 

 a foot high or a little more. It should have a warm, 

 sheltered place. Narbonense is a very popular kind 

 with blue, white-centred flowers, much used in herba- 

 ceous borders. It grows about two feet high and 

 blooms in May. Treatment of the last two species as 

 for Alpinum. Perenne is the well-known blue perennial 

 Flax. It grows a foot to eighteen inches high, and 

 bears blue flowers in June. Its white variety, album, 

 is a popular plant for rockeries and borders. These 

 will thrive in ordinary garden soil, and may be propa- 

 gated in the same way as the other herbaceous kinds. 



LITHOSPERMUM (Gromwell).— Dwarf shrubs, 

 best represented in most gardens by the low, rambling 



