PLANTS WORTH GROWING 105 
One only needs to see the hard, impregnable- 
looking face of a gaunt steep chalk cliff clothed 
with the red Valerian, as Centranthus ruber is called, 
to realize that this is a plant of marvellous vitality, 
and neither its sleek, glaucous foliage, nor its closely 
packed heads of small red tubular flowers are lacking 
in beauty. When once young plants are established 
new stock may always be obtained by simply 
allowing seeds to scatter themselves around. 
Cephalaria. — The giant yellow Scabious is very 
useful where one requires a screen for an ugly 
corner or a big tall plant to stand boldly over its 
neighbours' heads. 
C. alpina and C. tartarica have both pale yellow 
flowers, while those of C. leucantha are cream. 
They are of Scabiosa form and, being borne on 
long stems, make pretty cut-flower decorations. 
There is no difficulty in their culture, but it is 
advisable to divide and replant about every third 
year. 
Cerastium. — White-leaved plants with trailing 
stems and marvellously free growth, Cerastium 
Biebersteinii and C. tomentosum are capital plants 
for covering earthenware edging tiles, for carpeting 
beds of Phloxes, Delphiniums, etc., or for planting 
on graves. During Spring and Summer the white 
flowers are produced with such riotous freedom 
that they might well be called Snow Carpet, and 
when the plants overrun bounds all that is necessary 
is to cut them back with the shears. 
