24 Commercial Gardening 



(or argenteus), a shrubby species 1-3 ft. high, with lance-shaped silvery- 

 haired leaves and pale rosy flowers in summer; almost hardy. C. mauri- 

 tanicus, a trailing North African perennial, with ovate roundish leaves and 

 blue flowers with white centre, is often grown as a hanging plant for 

 pots and baskets and for draping stones in rockeries. It may be raised 

 from seeds, cuttings, and division. 



Coreopsis (Calliopsis). The finest species for market work is C. grandi- 

 flora, a beautiful North American biennial, 1 J-2| ft. high, with erect slender 

 stems and brilliant yellow flower heads. It is an excellent plant for 

 cutting during the summer and autumn. It is best raised from seeds 

 sown each year in April or May, afterwards transplanting the seedlings 

 1 ft. apart in rows 18 in. asunder to flower the following year. Basal 

 shoots without flower buds may also be detached in August and September, 

 and dibbled in during showery weather. They will root and flower the 

 next year. The best perennial for cutting is C. lanceolata, very similar to 

 but not so fine as C. grandiflora. Both kinds find a sale for the plants as 

 well as the flowers. Amongst the annual kinds the best are Drummondi, 

 aristosa, Atkinsoniana, and coronata, all yellow, the two last-named 

 having a reddish-purple blotch. C. tinctoria and its variety atrosan- 

 guinea are deep blood-red forms. 



Cornflower (Centaurea Cyanus). A well-known and charming native 

 annual or biennial, 2-3 ft. high, with narrow downy leaves, and heads of 

 bright-blue flowers in summer and autumn. It is an excellent plant for 

 cut flower, and a trade is also done in the plants in spring. There are 

 several varieties, including Emperor William, deep blue, florepleno, double, 

 as well as rose, purple, and white varieties. Seeds may be sown in autumn 

 to produce good plants for sale in spring, and also for early flower. Seeds 

 are also sown in gentle heat in spring, or in shallow drills in the open air. 



Corydalis (FUMITORY). Only a few species are dealt in by growers. 

 The plants are recognized by their grey-green, divided, fern-like leaves and 

 trusses of irregular flowers. Both tuberous- and fibrous-rooted varieties 

 grow almost in any soil, and look well massed. The kinds worth attention 

 are: bulbosa, 6 in., purple and white; capnoides, 1 ft, sulphur white; lutea, 

 6 in., yellow; thalictrifolia, nobilis, and Wilsoni, all yellow-flowered: and 

 cheilanthifolia, a fine dwarf rock plant, with beautifully dissected leaves. 



Cosmos bipinnatus. This graceful Mexican annual finds a sale in the 

 young stage for bedding-out purposes in early summer. It grows about 

 3 ft. high, has finely divided leaves, and bright rose, purple, or white 

 flower heads, freely produced in w r arm seasons. It is easily raised from 

 seeds sown in gentle heat in March, the young plants being hardened off 

 for sale by May in small pots or boxes. 



Crocus. There are many species of Crocus, some flowering in spring, 

 some in autumn, but the natural species are only a commercial commodity 

 amongst specialists, botanical gardens, and educational horticultural estab- 

 lishments. Many of them are lovely garden plants worthy of more ex- 

 tended cultivation. In this volume, however, attention need only be paid 



