ORNAMENTAL PLANTS OF HORTICULTURE VALUE

Selection of perennials

About 25-35 species, depending on classification, in Europe, North Africa and Central Asia. In the FSU about 15-20 species. Some species are biennials, others perennials. Two have been tested in St.-Petersburg, and can be recommended for gardens, especially for the rock garden.

R. alpestris (Kar. et Kir.) Boriss.

Central Asia (Tien Shan, Pamiro Alay, Dzungarskiy Alatau) and western China. On the gravelly soil, in rocky places, on cliffs at 1,500-3,000 m.

Leafy rosettes form a dense carpet. Rosette leaves elongate-lanceolate, 2.0-3.5 cm x 0.5 cm. Flowering leafy stems lateral, 3.0-8.0 (13) cm. Inflorescence an umbel-like panicle, with small white or pink flowers. V - evergreen plants. Fl - June or July. Fr - July or August. P - easly by division and by seed. Can grow in full sun and also in shady sites. Well suited to the rock garden. Z 5 (4). New.

R. platyphylla (Schrenk) Berger

Central Asia (Tien Shan, Dzungaro-Tarbagatay) and northwestern China. In rocky places, on cliffs and slopes.

Rosettes solitary or in groups of 3-5. Each rosette 5-10 cm diam. Leaves spathulate, 4.0-5.0 cm x 2 cm. Flowering stem erect 10-15 cm. Inflorescence an umbel-like panicle with numerous white flowers. V - evergreen plant. Fl - June. Fr - August. P - by seed and division. Not carpet-forming. In St. Petersburg suffers in winter without snow cover. Good for the rock garden and for slopes. Z 5 (4). New.