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: Northern Dewberry

General Information

Rubus flagellaris is a very variable, deciduous shrub producing each year a cluster of spiny, usually creeping, sometimes low-arching and then creeping stems from a perennial rootstock; the stems can be 2 - 4.5 metres long[]. The stems only produce leaves, and do not flower, in their first year, forming usually erect, flowering branches up to 120cm tall in their second year and then dying after fruiting
The plant produces a large, tasty fruit and is commonly harvested from the wild for local use as a food, it is also used medicinally. It has often been grown as a fruit crop in the USA, several cultivars have been developed[].

Known Hazards

None known

Botanical References

,

Range

Eastern and central N. America - Ontario and Quebec, south to northern Mexico, Texas and Florida.

Habitat

Dry fields, openings and borders of thickets[] in slightly acid soils[]. Woodlands, savannahs, pine barrens, prairies, meadows, rock outcrops, disturbed areas, dry to seasonally wet soil; at elevations up to 1,000 metres[]

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	0.20 m
Pollinators	Insects, Apomictic
Self-fertile	Yes
Cultivation Status	Cultivated, Wild

Cultivation Details

Easily grown in a good well-drained loamy soil in sun or semi-shade[, , ].
This species is sometimes cultivated for its edible fruit - there are some named varieties[, , ].
The plant produces apomictic flowers, these produce fruit and viable seed without fertilization, each seedling is a genetic copy of the parent[].
Plants in this genus are notably susceptible to honey fungus[].
Rubus flagellaris is extremely polymorphic, ranging from plants with low-arching (and later creeping) stems and relatively few prickles to low, creeping plants with abundant prickles. Individual plants in some years will produce abundant, arching, poorly armed stems, and in others creeping, well-armed stems. Prickle shape also varies in these plants both within a year and among different years. Local variants seem to readily intergrade with other variants; over the entire North American range of what would be known as section Procumbentes, a continuum of variation seems to be common[]

Edible Uses

Fruit - raw or cooked in pies, preserves etc[, , , , , , ]. A rich flavour[]. The black, sometimes dark red, globose to cylindrical fruit is 10 - 20mm in diameter[, ].

Young shoots - peeled and eaten raw[]. They are harvested as they come through the ground in spring and whilst they are still young and tender.

The dried leaves make a fine tea[].

Medicinal

The root is astringent, stimulant and tonic[]. An infusion has been used in the treatment of diarrhoea, venereal disease and rheumatism[]. An infusion has been used as a wash in the treatment of piles[]. The root has been chewed as a treatment for a coated tongue[].

The leaves are astringent[]. An infusion has been used in the treatment of diarrhoea[].

Other Uses

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

Propagation

Seed - requires stratification and is best sown in early autumn in a cold frame. Stored seed requires one month stratification at about 3°c and is best sown as early as possible in the year. 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.
Cuttings of half-ripe wood, mid summer in a frame[].
Tip layering in July. Plant out in autumn.
Division in early spring or just before leaf-fall in the autumn[].