THE ROCK-WALL IN SUN 19 



so commonly fatal to it, it will thrive and flower 

 abundantly. 



This species, with other Campanulas that are 

 absolutely saxatile, should in England always be 

 grown in a wall or perpendicular rock-work. The 

 same treatment suits C. Raineri, the yellow-flowered 

 C. petraa of the Tyrol, and Campanulas muralis, 

 Elatine, elatinoides, excisa, macrorhiza, and mirabilis. 

 That the same plan is suitable to C. isophylla may 

 be seen by the illustration showing a tuft flowering 

 in a wall facing south-west, in a garden thirty-five 

 miles south-west of London. 



Places should also be given to the tenderer of the 

 Lithospermums, L. Gastoni and L. graminifolium. 

 Graminifolium is a neat bushy-looking plant ; both 

 have the flowers of the fine blue colour that is so 

 good a character of the genus. In hottest exposures 

 in Devon and Cornwall and the Isle of Wight there 

 would even be a chance of success with L. rosmarini- 

 folium, the " Blue Flower" of the Island of Capri. 

 Its colour may be said to be the loveliest blue in 

 nature. It has not the violent intensity of the Gen- 

 tian, but a quality entirely its own. If one may 

 without exaggeration speak of a blue that gives the 

 eye perfect happiness, it would be this most perfect 

 blue of the lovely Gromwell of the cliffs of Capri. 

 But it must have sun and air and full exposure, 

 or the colour is wanting in quality, therefore it is 

 not a plant for the unheated greenhouse. The easily 

 grown Z. prostratum likes a rather cooler place, 

 and is more a plant for the rock-garden or for 



