The genus Rubus, (especially the blackberries, which are often loosely referred to as Rubus fruticosus agg.) presents some of the most difficult taxonomic problems. This is partly due to the frequency of polyploidy; also to the frequent occurrence of hybridization; and also due to apomixis, where minor differences between plants are preserved because seedlings are genetically identical to their parent. As a result, differences of opinion on the number of species to be recognized from a given region can vary tremendously (for example, a treatment by M. L. Fernald[] in 1950 recognized 205 species for the northern half of the eastern United States plus parts of southeastern Canada, whilst H. A. Gleason and A. Cronquist in 1991 recognized only 25)[]. Where possible, a relatively conservative approach is taken here[].

Common Name: Pacific Dewberry

General Information

Rubus ursinus is usually an evergreen shrub, producing each year a cluster of prickly, low-arching to creeping biennial stems from a woody rootstock; the plant is usually up to 20cm tall, the low arching stems can creep for up to 6 metres, often rooting at the nodes[, ].
This species is one of the best quality blackberries and is widely harvested from the wild for its edible fruits - the plant also has various other edible and medicinal uses. The plant is often cultivated and several cultivars, including some thornless ones, have been developed[].

Known Hazards

None known

Botanical References

, ,

Range

Western N. America - British Colombia, Washington, Idaho, Montana, Oregon, California, Baja California

Habitat

Waste places, fields, canyons etc; at elevations up to 1,000 metres[]. Woodlands, shrublands, open or disturbed areas, dry to damp soil; at elevations up to 1,600 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	0.60 m
Pollinators	Insects
Self-fertile	No
Cultivation Status	Cultivated, Wild

Cultivation Details

Easily grown in a good well-drained loamy soil in sun or semi-shade[, , ]. Rubus species in general grow well on a variety of barren, infertile soils - this species tolerates a wide range of soil textures and pH but requires adequate soil moisture for good growth[]. It appears to be tolerant of periodic flooding by brackish or fresh water[].
This species is the parent of many hybrid cultivated forms[], including the loganberry and the primus berry[].
Some botanists include the cultivated loganberry (treated here as a separate species, Rubus loganobaccus) under this species[].
Plants are tolerant of fire - top growth is usually killed but the plant resprouts rapidly from the roots[].
A dioecious species, both male and female plants are required if fruits and seed are to be produced[].
Plants in this genus are notably susceptible to honey fungus[].
Of agricultural significance, this species is a parent of some important cultivars, including the loganberry and the boysenberry[].

Edible Uses

Fruit - raw or cooked and used in pies, preserves etc[, ]. The fruit can also be dried for later use[]. A sweet flavour[, , , ]. The fruit can vary in flavour, the best forms have a large, sweet and well flavoured fruit[], whilst some forms are large but sour or insipid[]. The black, sometimes red or purple, rarely white, globose to cylindrical fruit is 10 - 25mm in diameter[]. The fruit can be up to 4cm long[].

Young shoots - raw or cooked like asparagus[]. They are harvested in the spring as they emerge through the soil and are still tender.

A tea is made from the fresh or dried leaves[, , ].

The young shoots can be made into a tea, usually mixed with the young shoots of other Rubus species[].

The half-ripe fruits can be soaked in water to make a pleasant drink[].

Medicinal

The dried bark of the root is astringent and has been used in the treatment of diarrhoea and dysentery[].

A decoction of the roots has been used in the treatment of diarrhoea and dysentery[].
The roots have been used as a disinfectant wash on infected sores[].

The fresh fruit has been eaten in the treatment of diarrhoea[].

A decoction of the entire vine has been used in the treatment of stomach complaints, diarrhoea and a general feeling of sickness[].

A decoction of the vines and roots has been used in the treatment of vomiting and the spitting of blood[].

An infusion of the leaves has been used in the treatment of stomach complaints[]. (as Rubus macropetalus)

Agroforestry Uses:

This species is a vigorous competitor which commonly invades disturbed sites created by logging, fire, or other types of disturbance. Most, if not all, thicket-forming species of Rubus have good erosion control value. They usually grow satisfactorily on barren and infertile soils and invade and occupy eroded areas. They also establish quickly on burns, old fields, and logged areas. Forming extensive and nearly impenetrable thickets, they can provide excellent cover for wildlife as well as nesting sites for small birds. They are often natural pioneer species, paving the way for woodlands to develop, but they should only really be used within their native range in order to avoid any risks of them invading other habitats[, ].

Other Uses

Because of the high fruit quality of this species, it is used in blackberry breeding programmes[]. (as Rubus macropetalus)

A purple to dull blue dye is obtained from the fruit[].

Propagation

Seed - requires stratification, is best sown in early autumn in a cold frame. Sow stored seed as early as possible in the year in a cold frame and stratify for a month at 3°c if sowing later than late winter. Prick out the seedlings when they are large enough to handle and grow on in a cold frame. Plant them out into their permanent positions in late spring of the following year.
Tip layering in July. Plant out in autumn.
Division in early spring.