Black Raspberry

Black raspberries resemble blackberries, but when ripe, the fruits fall away as a caplike unit from the receptacle. Leaflets appear white underneath. The canes are whitish-coated when young; they arch down and take root at the tips. Native and scattered statewide.

Black raspberry is an arching shrub, the young canes reaching a height of 3–7 feet, but as the stems grow longer, they arch down and take root at the tips.

Leaves are alternate, compound with 3 or 5 leaflets; all leaflets broadly egg-shaped to lance-shaped; the end leaflet commonly 2¾–3¼ inches long, tapering to a narrow point, the margin sharply and unequally double-toothed; side leaflets smaller and narrower, more or less lobed; leaflets on flower canes smaller, perhaps 2½–3¼ inches long, 1½–2½ inches wide; upper surface on all leaflets dark green, slightly hairy; lower surface densely white with matted hairs; leaf stalk 2–2½ inches long, smooth and usually bearing short, stout, curved prickles.

Twigs are flexible and smooth, the first-year canes with a whitish coating that rubs off; they are bluish green in summer, turning purple (or rarely yellowish green) in winter; prickles are broad-based and recurved (bend backward).

The trunk-like older canes have a smooth bark, are reddish purple with a whitish coating, the prickles or thorns recurved and stout; the wood is soft, white, with a large pith.

Flowers April–June, in tight clusters of 3–7 flowers on the end of shoots; the flower stalks are hairy and bear stout-hooked prickles; flowers are ½–¾ inch across; petals 5, white, narrow, stamens numerous.

Fruits June–July, firm and compact, the center hollow and thimblelike, purplish black, aromatic, mostly globe-shaped with a flattened base, about ½ inch across, becoming detached as a unit from the receptacle; seeds are straw-colored, egg-shaped to crescent, the surface net-veined.

Similar species: Rubus is a large genus with about 30 species recorded in Missouri. Globally, there are some 1,350 species. Included in the genus are blackberries, raspberries, loganberries, dewberries, and brambles. The members of genus Rubus often interbreed and hybridize, and the canes often change their appearance between first and second growing seasons, making them a tricky group even for botanists to sort out.

The genus Rubus is so large and complex that botanists divide it into 5 subgenera and numerous “sections.” Black raspberry is in subgenus Idaeobatus, the raspberry subgenus, and compared to the subgenus including blackberries and dewberries, this group of plants is somewhat easier to sort out. Members of the raspberry subgenus share the following characteristics:

• Leaves on the first-year canes are pinnately or palmately compound, felty-hairy (white) on the undersides.
• The ripe fruits fall freely, intact, from the receptacle (carpel), looking like a little cap or bowl.
• The sepals are long-tapered to a threadlike tip.

In Missouri, 4 species in the raspberry subgenus have been recorded in the state. Black raspberry is by far the most common and widespread. The rest are less common. The red raspberry you are familiar with from the grocery store is included, but it apparently does not last long in nature, out of cultivation:

• Red raspberry (Rubus idaeus var. strigosus). Differs from our other raspberries with its erect to arching canes that do not root at the tips, and purplish-red fruits. Introduced, known only from historical specimens from Barry and Jackson counties, where a few plants appeared to be growing out of cultivation (one, for example, was a seedling growing along a logging road). This native American red raspberry originally occurred in the northeastern United States and adjacent Canada, but not in Missouri. Botanists debate whether our North American raspberry and the European red raspberry (R. idaeus var. idaeus) are the same or different species. Where they are regarded as separate species, American red raspberry is labeled R. strigosus and European red raspberry is R. idaeus. Most red raspberries cultivated in Missouri are domesticated versions of the European red raspberry.
• Japanese raspberry (Rubus parvifolius). The first-year canes are not whitish-coated; central leaflets on first-year canes are reverse-ovate (with the widest part toward the outer tip); the flower petals are pink or reddish; the ripe fruits are glossy red. Introduced, native to Asia and Australia; in Missouri, known only from Greene County, where it has been found near the Dickerson Park Zoo; the population has continued to expand locally. It typically grows on the edges of mesic upland forests, along roadsides, and in open disturbed areas. In Iowa, some introduced populations appear to be expanding and may invade native prairies and savannas.
• Wineberry (Rubus phoenicolasius). Introduced, native to Asia; uncommon and sporadic in southern Missouri; occurs in bottomland forests, disturbed openings of rich upland forests, and bases and ledges of bluffs, also along railroads and roadsides. Identify it by its slender, straight prickles and red to purple hairs, many of which are gland-tipped; flower petals are white to pale pink; sepals covered with reddish, gland-tipped hairs; fruits orangish red. In some states, it is considered an invasive nonnative, forming dense thickets that crowd out native plants.