CHOICE PLANTS FOR ROCK GARDENS 131 
Pusilla alba, 3 inches, white. June to September. 
Rotundifolia flore pleno, r foot, double dark blue. June 
to September. 
Rotundifolia soldanelliflora plena, semi-double. 
Van Houttei, 2 feet, with spikes of very large pendent 
flowers of fine purple. June to August. 
Zoysii, 3 inches, with large azure-blue flowers. Mid- 
summer. 
CERATOSTIGMA PLUMBAGINIOIDES.—Saddled with an 
atrocious name, this is a plant of unique individuality and 
exceptional merit. First we may mention that it flowers 
in autumn, when many subjects have become colourless. 
Its flowers are of an uncommon shade of blue, generally 
described as cobalt blue. It throws up a quantity of erect 
red stems, clothed with large, particularly glossy and bright 
green foliage, which takes on delightful autumn tints of 
red and bronze. The best position for the plant is low 
on the rockery in a sunny position, with a good depth 
of soil, preferably turfy loam and fibrous peat. It will 
thrive in shade, but does not bloom so freely, and the 
foliage develops less colour than in a sunny spot. Cuttings 
taken off at a joint when about 3 inches long will root 
in sandy soil under a bell glass or hand light. 
Coponopsis OVATA.—A trailing plant with bell-shaped 
flowers, outwardly of a greyish blue, the interior of the 
blossoms constitute the chief charm, for it is beautifully 
speckled with yellow and white. On this account the 
plant is particularly well adapted for growing over ledges 
of rock as high as will enable one to look up to its dangling 
blossoms. 
