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: Giant Colombian Blackberry

General Information

Rubus nubigenus is a deciduous shrub producing each year a cluster of scrambling, prickly, biennial stems from a woody rootstock; the stems can grow 2 metres or more long. The stems only produce leaves, and do not flower, in their first year of growth; forming flowering branches in their second year and then dying after fruiting.
The plant is harvested from the wild for local use as a food. It is cultivated at higher elevations in Peru and Colombia, and occasionally elsewhere, the fruit being sold in local markets[, ].

Known Hazards

None known

Botanical References

Range

S. America - Bolivia, Peru, Ecuador, Colombia.

Habitat

Found at elevations between 2600 to 3400 metres[].

Properties

Edibility Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	2.00 m
Pollinators	Apomictic
Self-fertile	Yes
Cultivation Status	Cultivated, Wild

Cultivation Details

A plant of tropical, highland climates, it also has potential for growing in subtropical and temperate areas.
Easily grown in a good well-drained loamy soil in sun or semi-shade[, , ].
Attempts to grow this species outside its natural range have met with failure[].
Plants in this genus are notably susceptible to honey fungus[].

Edible Uses

Fruit - raw or cooked[]. A loganberry-like flavour[]. This species has probably the largest fruit of the genus, it is up to 50mm long and 25mm wide - fruits as large as a hen's egg have been seen[].

Medicinal

None known

Other Uses

This species is of interest in breeding programmes because of the large size of its fruits[].

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

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[].