Centaurea Macrocephala

Centaurea Macrocephala, the Giant Knapweed, with its large heads of yellow flowers, is a notable plant; and C. montana, the blue perennial Cornflower, is popular.

Red And White Valerians (Centranthus Ruber)

Red And White Valerians (Centranthus Ruber) are given to forming semi-wild colonies, and do not object to chalky banks.

Cephalaria Alpina

Cephalaria Alpina, sometimes known as the Giant Scabious, is a yellow-flowered perennial growing from four to five feet high.

The Cerastiums

The Cerastiums, or Snow-in-Summer, make dense carpets of white foliage on the rockery and in the border. Biebersteinii and Tomentosum are both popular species.

Cheiranthus Marshalli

Cheiranthus Marshalli is a beautiful bright orange Wallflower-like plant (the Wallflower bears the botanical name of Cheiranthus Cheiri), of which seeds can be got sometimes. It is a hardy perennial, of compact habit, and blooms freely, so that it is well worth growing. Its height is about fifteen inches.

Chelone Barbata

Chelone Barbata, which some seedsmen offer, is really a Pentstemon (P. Barbatus). It grows about two feet high, and has red flowers; Torreyi is a larger form of it.

The Giant White Shasta And Moon Daisies

The Giant White Shasta And Moon Daisies (Chrysanthemum Leucanthemum and C. Maximum) are valuable border plants, growing about two feet high, and spreading, in the case of large clumps in rich, moist soil, to four or five feet across.

Cimicifuga Cordifolia

Cimicifuga Cordifolia, the Bugwort, with its tall racemes of white flowers, is a handsome plant, worth growing in any border.

The Cistuses, Or Rock Roses

The Cistuses, Or Rock Roses, can be raised from seed if desired.

Convolvulus Mauritanicus

Convolvulus Mauritanicus is a splendid trailer, with large violet flowers, which one sometimes sees on large rockeries.

Coreopsis Grandiflora And C. Lanceolata

Coreopsis Grandiflora And C. Lanceolata are two good yellow perennial species of a genus which is perhaps best known through its annual members, Coronata, Drummondii, and Tinctoria. C. Lanceolata is a good plant.

Coronilla Varia

Coronilla Varia, the Crown Vetch, with rose flowers, and growing about eighteen inches high, is also an excellent border plant.

Corydalis Nobilis

Corydalis Nobilis, the Fumitory, a dwarf plant with Ferny foliage and yellow flowers, is pretty, and will thrive in shade, likewise on poor chalky land. It spreads rather too fast if left uncurbed, almost becoming a weed, so that it must be kept in check.

The beautiful spotted Gum Cistus, Cistus cyprius or ladaniferus maculatus, a charming shrub for dry rockeries.