_), orange hawkweed
(_Hieracium auranticum_), herb Robert (_Geranium Robertianum_),
coltsfoot (_Tussilago Farfara_), Solomon's seal (_Polygonatum
biflorum_), foam flower (_Tiarella cordifolia_), bloodroot (_Sanguinaria
Canadensis_), and some of the violets. These are but a few names, and
random ones at that. Some of them, the coltsfoot, cranesbill, celandine,
and toadflax, spread too rapidly, but by careful watching and not
allowing the seed to ripen, they may be kept within bounds. There are
many such plants that will take all the room in sight if they are
allowed to, and they must be watched closely, or else discarded
altogether. Some of them answer a good purpose by giving the rock garden
a quick start, after which they may easily be reduced or thrown out
altogether. There need be no compunction about discarding. Certain
plants, like certain friends, you enjoy having for a visit, but do not
care to see remain forever and a day.

Annuals as a class are not desirable for the rock garden; for one thing,
the care of renewal is too great. Biennials are almost as much care, but
in each case there will always be exceptions that are a matter of
individual preference. Few, for example, would have the heart to reject
the dainty little purple toadflax of Switzerland (_Linaria alpina_),
just because it is a biennial. The main dependence, however, must be
placed on perennials--the plants that, barring accidents, last
indefinitely. These should be mostly species; if horticultural, do not
use the bizarre--Darwin tulips, for example, or the Madame Chereau iris.
Nor, with rare exceptions, should double flowers be used. A double
daffodil looks horribly out of place, while the double white rock cress
(_Arabis albida_) will pass.

The easy rock garden plants, where the material is not taken from the
wild, are to be found in most of the large hardy gardens of the East.
Some of them are natives of Europe or Asia, and more than is commonly
suspected are at home in other parts of the United States. Among the
best of these for carpets of bloom are _Phlox subulata_, _Phlox
am[oe]na_, _Aubrietia deltoidea_, maiden pink (_Dianthus deltoides_),
blue bugle (_Ajuga Genevensis_), white bugle (_Ajuga reptans_), woolly
chickweed (_Cerastium tomentosum_), creeping thyme (_Thymus serpyllum_),
dwarf speedwell (_Veronica repens_), _Saponaria ocymoides_, alpine mint
(_Calamintha alpina_), and pink, white, and yellow stonecrops (sedum).
All of them fairl