ORNAMENTAL PLANTS OF HORTICULTURE VALUE

Selection of perennials

60-100 species, of almost cosmopolitian distribution. About 85 in the FSU. Some are annuals, some low, mostly creeping perennials, among which well-known plants used in rock gardens, e.g. C. alpinum L.

C. biebersteinii DC.

Crimea. On stony slopes and rocks.

Mat-forming evergreen plant with flowering stems about 40 cm. All parts densely hairy. Leaves linear, sessile, 2-5 cm x 0.2-0.5 cm grey-white. Inflorescence a loose semi-umbel of 8-11 white flowers 2.5 cm diam. V - throughout the year in a mild climate, in St. Petersburg spring generation of leaves in May. Fl - May-June for one month. Fr - July-August. P - by seed or cuttings. Flowers the year after sowing. Requires a sunny position. Z 4.

C. purpurascens Adams

Caucasus, northwestern Iran and Turkey. Alpine and subalpine meadows, stony screes.

Mat-forming plant, carpet of 20-30 cm thick. Basal leaves elongate-elliptic, stem leaves sessile, ovate-lanceolate. Inflorescence an umbel. Flowers minute, white. V - all seasons in mild climates, in St. Petersburg, spring generation of leaves in April. Fl - May-June. Fr - July. P - by seed or cuttings. Flowering the year after sowing. Requires a sunny location. Z 4.

C. argenteum Bieb., C. kazbek Parrot, C. multiflorum C. A. Mey., C. oreades Schischk. and C. szowitsii Boiss. are also of garden interest, all occur in the Caucasus and are mat-forming plants. C. szowitsii, for example, creates a wonderful, bright silvery cushion of foliage. C. lithospermifolium Fisch. Southern Siberia, Central Asia and northern Mongolia, on talus in alpine zone. Ground cover plant with large solitary flowers. All very good for the rock garden. Z 5. New.