Rubus armeniacus
Encyclopedia
Rubus
Rubus is a large genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae. Raspberries, blackberries, and dewberries are common, widely distributed members of the genus. Most of these plants have woody stems with prickles like roses; spines, bristles, and gland-tipped hairs are...
in the blackberry
Blackberry
The blackberry is an edible fruit produced by any of several species in the Rubus genus of the Rosaceae family. The fruit is not a true berry; botanically it is termed an aggregate fruit, composed of small drupelets. The plants typically have biennial canes and perennial roots. Blackberries and...
group Rubus subgenus Rubus series Discolores (P.J. Müll.) Focke. It is native to Armenia
Armenia
Armenia , officially the Republic of Armenia , is a landlocked mountainous country in the Caucasus region of Eurasia...
in southwest Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, and widely naturalised
Naturalisation (biology)
In biology, naturalisation is any process by which a non-native organism spreads into the wild and its reproduction is sufficient to maintain its population. Such populations are said to be 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.
Description
Rubus armeniacus is a perennial plantPerennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
which bears biennial
Biennial plant
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle. In the first year the plant grows leaves, stems, and roots , then it enters a period of dormancy over the colder months. Usually the stem remains very short and the leaves are low to the ground, forming...
stems ("canes") 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, stout, up to 2–3 cm diameter at the base, and green, or reddish-tinged above if open to bright sun. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
on first year shoots are 7–20 cm long, palmately compound
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
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 (rarely a single leaflet); the 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 flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are produced in late spring and early summer on panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....
s 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 petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
s.
The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
, in botanical
Botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...
terminology, is not a berry
Berry
The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....
, but an aggregate fruit of numerous drupe
Drupe
In botany, a drupe is a fruit in which an outer fleshy part surrounds a shell of hardened endocarp with a seed inside. These fruits develop from a single carpel, and mostly from flowers with superior ovaries...
lets, 1.2–2 cm diameter, ripening black or dark purple. Both first and second year shoots are spiny
Thorns, spines, and prickles
In botanical morphology, thorns, spines, and prickles are hard structures with sharp, or at least pointed, ends. In spite of this common feature, they differ in their growth and development on the plant; they are modified versions of different plant organs, stems, stipules, leaf veins, or hairs...
, 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.
Berry crop
The species was introduced to Europe in 1835, and Australasia and North America in 1885. It was valued for its fruit, similar to that of common blackberriesBlackberry
The blackberry is an edible fruit produced by any of several species in the Rubus genus of the Rosaceae family. The fruit is not a true berry; botanically it is termed an aggregate fruit, composed of small drupelets. The plants typically have biennial canes and perennial roots. Blackberries and...
(Rubus fruticosus and allies); but larger and sweeter, making it a more attractive species for both domestic and commercial fruit production. The cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
s "Himalayan Giant" and "Theodore Reimers" are particularly commonly planted.
Invasive species
Himalayan Blackberry was first introduced to America from Europe in the late 1800s as a cultivated crop. Because it is so hard to contain, HBB quickly got out of control, with birds and other animals eating the berries and then spreading the seeds. From this, HBB eventually spread to the Pacific Northwest, where it is now widespread.Rubus armeniacus soon escaped from cultivation and has become an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in most of the temperate world.
However, anthropogenic ecological disturbance often underlies damage that Himalayan blackberries appear to cause. In light of this, the species may perform a valuable ecosystem service by mitigating frequent disturbance (i.e. erosion control, deterring humans).