Ord._ CRUCIFERAE.

One of the alpine gems of our rock gardens, not in the sense of its
rarity, because it grows and increases fast. It came from Switzerland
about sixty years ago, and for a long time was esteemed as a biennial,
but it is more--it is perennial and evergreen; at any rate its new
branches take root, and so its perennial quality is established. Let the
reader imagine a shrub, 3in. high, much branched, and densely furnished
with pale green foliage, which hides all its woody parts, forming itself
into cushions, more or less dotted over with minute canary-yellow
flowers, and he will then only have a poor idea of the beauty of this
pretty alpine. It flowers in summer, autumn, and winter, and in certain
positions both its habit and flowers show to most advantage at the
latter season. At no other time during the year have my specimens looked
so fresh and beautiful as in January. This I have proved repeatedly to
be the result of position, shortly to be explained.

The flowers are produced in terminal racemes, are scarcely 1/2in. across,
cruciform in the way of the Wallflower, greenish-yellow, and delicately
scented. The leaves vary in shape on the various parts of the branches,
some being lance-shaped and others nearly spoon-shaped; the lower ones
being all but entire, and the upper ones, which are arranged in
rosettes, distinctly toothed. They seldom exceed an inch in length, more
often they are only half that size, but much depends on the position and
soil. In summer the foliage is greyish-green; later it is almost a
bright or clear green, the latter being its present colour. The habit is
branching and compact, by which it adapts itself to crevices and uneven
parts in a pleasing manner; and not only does it best adorn such places,
but from the fact of their dryness, they are better suited to the
requirements of this little shrub.

A sandy loam, such as will not bake, suits, and if mixed with a few
stones all the better--this will be found ample food for it; poor soil
and a dry situation grow this subject in its finest form. I may perhaps
usefully give the method by which my specimen is grown, after
experimenting with it in various parts of the garden, and also the
substance of a few notes I made of it. In pots the fine roots soon
formed a matted coat next the sides, when the foliage would turn sickly
and yellow, so that, useful as the practice is of growing alpines in
pots, it does not answer in this case.