40 ALPINES AND BOG-PLANTS 
open place, over any sunny rock. Besides all the innumer- 
able single and double varieties (Amabile is a double 
ball of crimson scarlet, and there is a similar lemon globe 
called Ball’s Green) of vulgare, notably a copper-coloured 
one from Mr. Wolley-Dod, and a beautiful big rose-pink 
variety, I grow also purpurewm and roseum, species so far 
doubtful as far as the flower is concerned. 'Then comes 
umbellatum, tall, erect, wiry-leaved, with heads of snow- 
white flowers. ‘This is tender and miffy, though less so 
than the, to me, impossible Tuberaria, so abundant by 
the roadside over the hills from Cannes. But our own 
most rare white-flowered native, Helianthemum polifolium, 
from Brean Down (you see masses of it, too, on the rail- 
way cuttings as you leave Dijon), is very valuable, and so 
is the tiny grey bush of HZ. linulatum, with its profusion 
of small lemon blooms. And a special favourite of mine 
is the too seldom seen HA. oelandicum, which I collected 
in the Oberland—a wee, frail thing, with little blossoms 
of brilliant gold. 
As for Helianthemum vulgare—type of all its kin—no 
culture, in the sun, comes amiss to it, but there is one 
cultural recommendation I should very strongly make to 
every one who grows it. Cut it over hard, as soon as the 
spring blossom is done. ‘This causes the plant to break 
anew, forming a neat round tuft; and has the further 
advantage of securing a second season of bloom later on. 
Not to mention that otherwise the Rock-rose grows leggy, 
lanky, sickly, and ultimately moribund if left too long 
to its own devices. The same advice I have already 
given about Potentilla fruticosa, and it is, of course, of 
the first importance in the case of all slender, tall-grow- 
ing shrubs, from Lavandula vera to Boronia megastigma. 
‘The same applies, too, to Lreica and Pernettya. Past 
Pernettya I slide, for though useful little berried heaths, as 
it were, in the rock-garden, they have never made any 
