io6 THE NEW GARDENING 



glass. Stone chippings may also be sprinkled around 

 it. Or it may be planted in the crevice of a nearly 

 vertical wall. Sibiricum, often offered as a species, is 

 simply a larger variety. 



LIN ARIA (TOADFLAX). The species Alpina, with 

 deep mauve flowers in July, and grey leaves, is a good 

 rock plant. Cymbalaria, the " Kenilworth Ivy," and 

 the variety rosea are good for dry spots. Ordinary soil. 



LITHOSPERMUM (GROM WELL) .The best -known 

 member of this genus is L. prostratum, a vigorous 

 creeper with brilliant blue flowers in summer. Heavenly 

 Blue is a somewhat paler form of it. Canescens has 

 tubular orange flowers. Intermedium, with blue tubular 

 flowers on 6-inch stems in early summer, is a beautiful 

 species. Gastoni is a lovely rare Alpine, blue with white 

 centre, about a foot high. Rosmarinifolium, blue, 

 nine inches high, is also worth mentioning ; it is an ever- 

 green. They like gritty loam, with plenty of moisture. 

 A dry site with poor soil does not suit them, for although 

 they may bloom in beautiful colour the first year of 

 planting they are likely to dwindle away afterwards. 

 Propagation by division and cuttings in spring. 



MACROTOMIA. See Arnebia. 



MERTENSIA. Beautiful plants, of which the best 

 known is Virginica (syn. pulmonarioides) , the Virginian 

 Cowslip ; it bears blue, rose-tinged flowers on 1 5-inch 

 stems in spring. Echioides is dwarfer and has deep, 

 gentian-blue flowers. There is a variety of this called 

 elongata, which grows a foot high and is brilliant blue. 

 Primuloides, blue with yellow eye, is another pretty plant. 

 Sibirica, blue, and its white and dark blue forms, are 

 well-known border plants. The Mertensias do best in 



