ORNAMENTAL PLANTS OF HORTICULTURE VALUE

Selection of perennials

About 250-300 species in Eurasia and South Africa, 100 in the FSU, mainly in the Caucasus, also in the European regions and in the Far East. Some Russian species are known in horticulture (e.g. D. chinensis L., D. campestris Bieb., D. carthusionorum L. and D. superbus L.). A number of species have been investigated in St. Petersburg. They are very ornamental and long-flowering plants.

D. imereticus (Rupr.) Schischk.

Caucasus (western regions). On limestone, on cliffs and slopes.

Stems numerous, branched 30-60 cm. Leaves linear-lanceolate, acute, 4-7 cm x 3-7 mm. Inflorescence of a few flowers produced on the top of the main stem and on the tops of the numerous axillary branches. Flowers pink, 2.5 cm across. V - early spring to late autumn. Fl - from June through autumn. Fr - in August or September. P - easy by seed or cuttings. Requires a sunny place and limestone soil. Suffers from excess water and frost during the winter. Well-suited for the rock garden and group planting. Z 6 (5). New.

D. raddeanus Vierh.

Caucasus (Transcaucasus). On limestone, in meadows in the alpine zone.

Cushion or mat-forming plant. Main stem becoming woody at the base. Leafy stem 5-13 cm, with two pairs of linear leaves, 2-4 cm x 2-3 mm. Flowers solitary, purple. V - evergreen plant. Fl - July and August. Fr - September. P - by seed or by cuttings. Requires limy soil, semishaded place in zone 6, in zone 5 requires winter protection. Good for flower beds, for group planting, for the rock garden and as a cut flower. Z 6 (5). New.

D. seravschanicus Schischk.

Central Asia (Pamiro Alay). On sunny sites, on rocky and steppe slopes.

Leafy stems numerous, woody at the base, branched in upper part, reaching 35-50 cm. Leaves linear, l 2.5-5.0 cm x 1-3 mm. Flowers white or pink, two or three per stem in terminal panicle, rarely solitary. V - early spring to late autumn. Fl - from June for one month or longer. Fr - July-August. P - by seed or cuttings. Requires a sunny place, drought-resistant. Z 5. Good for group planting. New.

D. turcomanicus Schischk.

Central Asia (Kopet-Dag). In rocky places, on cliffs and talus.

Plant 20 - 50 cm. Leafy stems numerous, woody at the base. Leaves linear 1-6 cm x 1-2 mm. Flowers white or light pink, with fringed petals, 2.5-3.5 cm diam., solitary at top of stem. V - from mid spring to late autumn. Fl - in nature May to end June. Fr - in July. P - by seed and cuttings. Requires a sunny position and light soil. Drought and heat resistant. Good for group plantings. Z 6 (5). New.