much hot sun. These and many similar plants can often
be planted on a =rockery facing south-east= (which aspect suits so many
sun-loving plants), by arranging bricks, stones, or small shrubs, so as to
shelter them from its hottest rays. _Aquilegias_, mentioned in the list of
border plants, look quite as well on a rockery, if moisture can be given
them, as their flowers are so delicate, and the leaves so fragile and
prettily coloured, especially in the early spring. The blue and white _A.
caerulea_, from the Rocky Mountains, is =a gem=, and the scarlet kinds are
very effective.

=For forming close green carpets=, _arenaria balearica_ is most useful; it
creeps over rocks and stones, covering them completely with its moss-like
growth, and hiding any hard, unlovely surfaces. The _campanula_ family is
=a host in itself=, many of the smaller varieties looking better on a
rockery than anywhere else. Some of these tiny bell-flowers have, however,
the very longest of names! _C. portenschlagiana_, for instance, is only
four inches high, and =a charming little plant= it is, and flowers for
months, beginning about July. The blossoms are purple-blue in colour, and
continue right into November, unless very hard frosts come to stop it. _C.
cespetosa_ is another variety well suited to rock-work, as it is even
smaller than the last.

=The alpine wall-flower=, _cheiranthus alpinus_, is a very choice little
plant; it has creamy-yellow flowers, borne on stalks a few inches high,
and, though each individual plant is biennial, they seed so freely that
they are practically perennial. A light, dry soil and a sunny situation
suits them; they will even grow on old walls, and very picturesque they
look perched up on some mossy old ruin.

=An attractive rock plant=, though rarely seen, is _chrysogonum
virginianum_; its flowers are creamy-yellow, and grow in a very quaint
manner; this plant =blooms the whole season through=. Plants of this
character should be noted carefully, as they help to give a rockery =a
well-furnished appearance=, so that one always has something to show
visitors.

For warm, dry, sunny nooks =rock-roses= are the very thing; where other
plants would be burnt up, the _cistus_ flourishes, for it requires no
particular depth of soil. _C. florentinus_ (white) and _C. crispus_ (dark
crimson), are two of the best.

=One of the most exquisite and interesting rock-plants= I have ever seen
is _clematis davidiana_, a plant only int