Himalayan Blackberry

Rubus armeniacus

''Rubus armeniacus'', Armenian Blackberry or Himalayan Blackberry, is a species of ''Rubus'' in the blackberry group ''Rubus'' subgenus ''Rubus'' series ''Discolores'' Focke. It is native to Armenia and Northern Iran, and widely naturalised elsewhere. Both its scientific name and origin have been the subject of much confusion, with much of the literature using one or the other of the two synonyms, and often mistakenly citing its origin as western European.
Oregon Blackberry A delicious berry that now grows all over the state like weeds is in season. You can see the different stages of the fruit in this image. The western side of Oregon is so prolific that it is rare that you don't see them growing along side every path and road that is not mowed or developed. Himalayan Blackberry,Rubus armeniacus

Appearance

''Rubus armeniacus'' is a perennial plant which bears biennial stems from the perennial root system. In its first year a new stem grows vigorously to its full length of 4-10 m, trailing along the ground or arching up to 4 m high. The stem is stout, up to 2–3 cm diameter at the base, and green or reddish-tinged above if it is exposed to bright sunlight. The leaves on first year shoots are 7–20 cm long, palmately compound with five leaflets. Flowers are not produced on first year shoots. In its second year, the stem does not grow longer, but produces several side shoots, which bear smaller leaves with three leaflets . These leaflets are oval-acute, dark green above and pale to whitish below, with a toothed margin, and thorns along the midrib on the underside. The flowers are produced in late spring and early summer on panicles of 3–20 together on the tips of the second-year side shoots, each flower 2–2.5 cm diameter with five white or pale pink petals.

The fruit in botanical terminology is not a berry, but an aggregate fruit of numerous drupelets, 1.2–2 cm diameter, ripening black or dark purple. Both first and second year shoots are spiny, with short, stout, curved, sharp spines. Mature plants form a tangle of dense arching stems, the branches rooting from the node tip when they reach the ground.
The Himalayan Blackberry, Rubus armeniacus. We are (un)fortunate to have both species of introduced blackberries in our yard. The two species can be easily distinguished by their leave shape. A description of the leave from E-Flora BC, “Alternate, evergreen, palmately compound, 5-20 cm long; leaflets 5 on first-year canes, mostly 3 on flowering canes, egg-shaped, 5-12 cm long, double-saw-toothed and abruptly sharp-pointed at the tip, green and smooth above, greyish-woolly beneath, the leaf-stalks and midveins beneath prickly; stipules linear.”
For comparison, https://www.jungledragon.com/image/80308/the_cutleaf_evergreen_blackberry_rubus_laciniatus.html Canada,Geotagged,Himalayan Blackberry,Rubus armeniacus,Spring

Naming

''Rubus armeniacus'' soon escaped from cultivation and has become an invasive species in most of the temperate world. Because it is so hard to contain, it quickly got out of control, with birds and other animals eating the fruit and then spreading the seeds.

References:

Some text fragments are auto parsed from Wikipedia.

Taxonomy
KingdomPlantae
DivisionAngiosperms
ClassEudicots
OrderRosales
FamilyRosaceae
GenusRubus
SpeciesR. armeniacus