RHAMNUS. Buckthorn. Widespread. A large group of trees and shrubs, many of them with spine-tipped twigs. Most have pointed-oval to lance shaped leaves, often quite decorative. Flowers are small and generally inconspicuous, borne in small clusters in the leaf-axils. However, the berries which follow can be quite showy. Most are rugged and easily grown, and have a variety of uses. Sun or light shade, reasonably well drained soil, occasional watering when established. Hardy to 10oF or less.
alaternus. Italian buckthorn. An evergreen shrub, easily trained as a small tree, growing 10-20’ tall. The main branches are erect to upsweeping, lined by virtual brushes of branchlets.The leaves are up to 2” long, pointed-oval in outline, and colored dark green above, pale green beneath, with a lacquered surface. Flowers are tiny and greenish, and many of the small blackish purple berries are hidden by the leaves. This is a nearly indestructible shrub, used in tall screens and hedges or trained as a small tree. ‘John Edwards’ is a vigorous, large leaved selection.‘Variegata’ is smaller and slower growing, with smaller leaves decorated by cream-colored margins. It is a more malleable plant for small landscapes.
californica. Coffeeberry. A native shrub with quite variable features. It is often large (8' or more), but there are nearly matting forms. It can be sparsely or densely branched, with broadly oval to lance shaped leaves, dark and often shiny above, pale beneath. Hairy-leaved forms were recently carved out by botanists into separate species and are not included here. Its clusters of small, greenish yellow blossoms are fragrant but inconspicuous. However, the large berries which follow and persist into winter are often quite showy, being heavily tinged with red or purple, often black when mature. Coffeeberry is adaptable and useful in a variety of landscape settings according to size and shape. Sun or light shade, many soils, moderate to occasional summer watering when established. Hardy in the following selections to 15oF or less.
‘Eve Case’. The most popular of the group, now almost a mainstream shrub. It is compact and of moderate growth, usually under 6' high. The stems are closely lined with flat 4” leaves, dark green and shiny on the upper surface. Its berries are unusually large, densely clustered and heavily tinged with red. Introduced by the Saratoga Horticultural Foundation.
‘Mound San Bruno’. A recent selection by Roger Raiche, making a broad, relatively low mound. It was originally described as reaching 3' by 7' in the ground after six years, but has already doubled that estimate in well-tended gardens. The plant is closely branched and has very dark leaves, narrower than those of the following selections. It should prove to be the best selection yet for large-scale ground cover.
‘Seaview Improved’. A seedling of the old Saratoga Hort. introduction, ‘Seaview’, this selection is the smallest yet, lying nearly flat on the ground. The leaves are only 2-3" long, flat, dark and shiny on the upper surface. The berries are densely clustered and red when ripe, making quite a show.
tomentella. This species includes a variety of entities once placed under R. californica and similar in overall appearance. The plants grow as much as 15’ tall, though usually half that figure, and are upright-arching to widely spreading in habit. The young stems are often reddish, developing attractive grey bark as they mature. They are lined by broadly to narrowly oval leaves, up to 4" long, often rolled under at the margins. Their color is deep green to blue green above in the typical form, grey with a dense coat of small hairs beneath. The flowers are small and greenish, like those of R. californica, and the berries are quite similar. The var. tomentella is simply the typical form. I recently stumbled on some particularly nice, bushy plants with exceptionally showy berries, jet-black when mature; reselections from their seedlings are forthcoming. The var. crassifolia is a very different plant, at least in its outward features. Though of typical size, it is more openly branched than tomentella, with fewer and usually larger leaves. These are densely felted with grey hairs on both surfaces, giving the plant an almost ghostly appearance. The berries in the current material pass through a beautiful, bright red phase before turning typically black. 10oF. or less.