Raspberries are perennial shrubs (a few species partly herbaceous) with trailing to erect stems, which are often spiny with weak to strong bristles or prickles. The leaves are alternate, deciduous or persistent, mostly with well-developed stipules and with whole blades or separated into leaflets. The stems are often biennial, leaf-bearing the first year (primocanes) and bearing flowers the second (floricanes). The flowers are mostly rather large, often showy, with the parts attached on a disk surrounding the ovary. They are regular, complete or sometimes either male or female, single (terminal or axil-borne) to several in clusters. The calyx have usually 5 lobes opening by valves, they are often more or less tail-tipped, spreading to bent backward, persistent in fruit. The 5 petals are white to red, erect to spreading, and are soon dropped. The stamens can range from 15 to 40-100 or more, the filaments are slender to evidently flattened, inserted with the petals at the outer edge of the elongated floral axis below the calyx. The several to many pistils are borne on a rounded to cone-shaped-oblong, often fleshy receptacle. The style is very thin to club-shaped. The mature fruit is an aggregation of rather weakly coherent drupelets separately or collectively dropped, often closely associated with the fleshy receptacle. The "pit" (stone fruit) is usually wrinkled or pitted. The genus consists of several hundred species worldwide, nearly cosmopolitan in range, but most common in the temperate regions of the Northern Hemisphere. The name comes from the Roman name for the plant.
Guide to Identify Presented Species of Genus Rubus
PLANTS USUALLY OVER 50 CM TALL
R. idaeus Wild Red Raspberry Stems prickly, widely branching, 100-150 cm tall. Rocky areas, montane zone.
Flowers small, white. Petals 5, oblong, 4-6 mm long. Sepals longer than petals.
Leaves divided into 3-5 leaflets, double-toothed, white-hairy beneath.
R. parviflorus Thimbleberry Shrub 50-200 cm tall. Open to wooded, moist to dry areas up to subalpine zone.
Flowers white, few in open clusters. Petals 5, broadly oval, 15-20 mm long.
Leaves large, 10-20 cm wide, with heart-shaped bases, palmately lobed.