CHOICE PLANTS FOR ROCK GARDENS 165 
the rockery or the alpine bed. It makes shrubby little 
plants about g inches to a foot in height, producing 
numerous spikes of tubular flowers of a lively ruddy purple. 
P. Menziesii is dwarfer, the shade of purple leans more 
toward violet, and the plant is neat and always pleasing. 
Very showy, with bright shining scarlet flowers, is 
P. Murrayanus, growing about a foot in height, and another 
distinct and pretty plant is P. Watsonii, the flowers of 
which are mainly purple, but sometimes mixed with white. 
P. humilis is one of the dwarfest of the tribe, with blue 
flowers in close heads, and another ideal plant for the 
rockery or for the alpine frame is P. Hallii, with flowers 
of a mauve shade verging on to violet. Of Pentstemon 
glaber we have several varieties, and all are good. Colours 
vary from rosy pink to lavender blue and rosy purple. 
The growth is tufted, with rosettes of long glossy foliage 
of a light shade of green. 
Quite a contrast and an uncommon note in the genus 
is afforded by P. antirrhinoides, which has yellow flowers, 
and with these one may consider he has a fairly repre- 
sentative collection of the dwarf-growing species most 
suitable for an Alpine garden. 
Puiox.—This is another extensive family that gives 
us, in addition to the universally popular large-flowered 
border varieties of the florist, quite an array of dwarf- 
growing, early and free-blooming plants for the various 
purposes with which we are now concerned. There is 
no real difficulty about the successful culture of alpine 
Phlox, yet it must be admitted that failures are frequent, 
quite a lot of plants dying off without apparent cause 
