EASILY GROWN ROCK PLANTS 89 
GYPSOPHILA.—It is not the ever popular Gypsophila 
paniculata which concerns a book on alpine and rock 
plants, but a few dwarf or prostrate species that will cover 
a good area with glaucous or light green foliage, and produce 
a goodly mass of minute airy flowers of white, or some- 
times delicate pink flowers. Lovers of chalk, the Gypso- 
philas are particularly useful in those places where a 
surface of stony gravel rests upon a chalky subsoil. The 
one thing Gypsophilas strongly object to is disturbance 
of the roots when once they have established themselves. 
Raising from seed is the best means of propagation, and the 
seedlings should either be planted in permanent quarters 
when quite young, allowing ample space for spreading, 
or they should be potted until required for planting out. 
G. prostrata and G. repens are both white, the latter having 
a pretty pink variety named repens rosea grandiflora. 
Another pink-flowered plant is G. mangini, while G. ceras- 
tioides is a particularly good plant of close-tufted growth, 
with unusually large flowers which are white, prettily 
veined with pink. 
HELIANTHEMUM.—There are quite a number of small, 
either compact or trailing flowering shrubs, that are as truly 
Alpine plants as are the sedums and saxifragas, and 
among them the Helianthemum is certainly one of the most 
charming and effective. In growth, the Helianthemum 
is not unlike the thyme of the kitchen herb border, slender, 
wiry, semi-prostrate stems being clothed with small, tough 
leaves, sometimes of a bright, glossy green, and in a few 
cases covered with a silvery or grey tomentum. The 
common name of the plant is “Sun Rose,” and there is 
