224 
The mountain pinks contain some of the choicest rock garden 
plants. Dianthus alpinus, a dwarf with enormous rose-pink flow- 
ers; D. neglectus, also dwarf, its pink flowers having the reverse 
of the petals a satiny buff; D. sylvestris, a little taller, with pink 
flowers on gracefully arching stems, are among the best. 
Dwarf species of Baby’s Breath (Gypsophila), include G. 
cerastioides from the Himalayas, white flowers with purple lines, 
produced very abundantly, and G. repens, trailing, with glaucous 
There is a double flowered form of 
peso 
— 
—y 
foliage and white flowers. 
the latter, one with pinkish flowers, and one variously known as 
var. major or var. monstrosa (Fig. 22), that reaches a height of 
a foot or eighteen inches. One of the best of the Sandworts, 
Arenaria montana, a straggler with large white flowers, is not very 
permanent with us. I have seen this spécies in England thriving 
amazingly ina brick wall laid up without mortar. A. stricta makes 
a cloud of linear foliage on fragile stems topped with small white 
Arenaria Bauhinorum (A. liniflora) about three inches 
flowers. 
The 
high is almost completely smothered with white flowers. 
Arenaria and closely allied Alsine, Sagina, and Cerastium, though 
often beautiful, will bear close watching in the rock garden as 
many of them are insidious invaders by underground runners 
or seeds, and quickly crowd out less robust plants in their vicinity. 
In this category belong Snow-in-Summer (Cerastium tomento- 
sum), having white leaves and flowers, and the somewhat stronger 
C. Biebersteinii with gray leaves and white flowers. 
Saponaria ocyinoides continues its sprawling career into June. 
en to 
— 
This, too, tries to take possession of the whole rock gar« 
display its white, pink, or parti-colored flowers, but it is easily 
controlled. The Pyrenean S. cespitosa is far less rampant. It 
has close tufts of shiny foliage, and rosy flowers on ascending 
stems of six inches or so. 
The Alpine Catchfly (Silene alpestris) makes close mats of 
foliage surmounted by myriads of pure white flowers on three- 
inch stems. S. acaulis, which might be so wonderful as a rock 
garden plant but which seldom is, has its pillows of foliage, formed 
of closely crowded rosettes of linear leaves, sparingly spangled 
with stemless flowers of bright pink. Under the right conditions 
