126 THE WILD GARDEN. 
chrysantha of Western America is the most hardy and enduring of 
the American kinds. The species are of a truly northern and alpine 
family, most abundant in Siberia. 
Wall Cress, Arabis.—Dwarf alpine plants, spreading in habit, 
and generally producing myriads of white flowers, exceedingly suitable 
for the decoration of sandy or rocky ground, where the vegetation is 
very dwarf. With them may be associated Cardamine trifolia and 
Thlaspi latifolium, 
which resemble the 
Arabises in habit and 
flowers. All these are 
particularly suited for 
association with the 
purple Aubrietias, or 
yellow Alyssums, and 
in bare and rocky or 
gravelly places, old walls, 
sunk fences, ete. 
Sandwort, Are- 
naria.— A most 'import- 
ant family of plants 
for the wild garden, 
though perhaps less so 
for lowland gardens 
where more vigorous 
types flourish. There 
are, however, certain 
species that are vigorous 
and indispensable, such 
as A. montana and 
A. graminifolia. The 
smaller alpine species 
are charming for rocky 
places, and the little creeping A. balearica has quite a peculiar 
value, inasmuch as moist rocks or stones suffice for its support. 
It covers such surfaces with a close carpet of green, dotted with 
numerous star-like flowers. Some of the smaller species, such as 
Arenaria cispitosa (Sagina glabra var.), better known as Spergula 
pilifera, might be grown in the gravel, and even used to convert 
bare and’ sandy places into carpets of Mossy turf. In certain 
M 
Siberian Columbine in rocky place. 
