Blackberry

The blackberry is an edible berry in the Rubus genus and the Rosaceae family. The fruit are botanically termed an aggregate fruit and they are produced on plants that typically have biennial canes and perennial roots. Blackberries and raspberries are also called caneberries or brambles. It is a widespread, and well known group of over 375 species, many of which are closely related apomictic microspecies native throughout the temperate Northern hemisphere and South America

In its first year, a new stem, the primocane, grows vigorously to its full length of 3-6 m (in some cases, up to 9 m), arching or trailing along the ground and bearing large palmately compound leaves with five or seven leaflets; it does not produce any flowers. In its second year, the cane becomes a floricane and the stem does not grow longer, but the flower buds break to produce flowering laterals, which bear smaller leaves with three or five leaflets.[2] First and second year shoots are usually spiny with numerous short curved very sharp thorns (thornless cultivars have been developed purposefully). Recently the University of Arkansas has developed primocane fruiting blackberries that grow and flower on first year growth much as the primocane (also called fall bearing or everbearing) fruiting red raspberries.

Unmanaged mature plants form a tangle of dense arching stems, the branches rooting from the node tip on many species when they reach the ground. Vigorous and growing rapidly in woods, scrub, hillsides and hedgerows, blackberry shrubs tolerate poor soils, readily colonizing wasteland, ditches and vacant lots.[1][3]

The flowers are produced in late spring and early summer on short racemes on the tips of the flowering laterals.[2] Each flower is about 2-3 cm in diameter with five white or pale pink petals.[2] The newly developed primocane fruiting produces flowers and fruits on the new growth.
A bee pollinating blackberries

The early flowers typically form more drupelets than the later ones as they develop more fully as the flower buds develop during the dormant period. This can also be a symptom of exhausted reserves in the plant's roots, marginal pollinator populations, or infection with a virus such as Raspberry bushy dwarf virus. Even a small change in conditions, such as a rainy day or a day too hot for bees to work after early morning, can reduce the number of bee visits to the flower, thus reducing the quality of the fruit. The drupelets only develop around ovules that are fertilized by the male gamete from a pollen grain.

In botanical terminology, the fruit is not a berry, but an aggregate fruit of numerous drupelets ripening to black or dark purple.

Blackberry leaves are also a food for certain caterpillars and grazing mammals, especially deer, are very fond of the leaves. See List of Lepidoptera that feed on Rubus

Cultivation and uses
Primary cultivation takes place in the state of Oregon located in the United States of America. Recorded in 1995 and 2006: 6,180 acres (25.0 km2) to 6,900 acres (28 km2) of blackberries, producing 42.6 to 41.5 million pounds, making Oregon the leading blackberry producer in the world.[4][5]. While Oregon may lead the world in volume of fruit produced, Serbia has tremendous acreage and Mexico has had dramatically increasing acreage and will soon lead the world in hectarage and production.

The soft fruit is popular for use in desserts, jams, seedless jellies and sometimes wine. Since the many species form hybrids easily, there are numerous cultivars with more than one species in their ancestry.

Good nectar producers, blackberry shrubs bearing flowers yield a medium to dark, fruity honey.
Blackberry flower.

The blackberry is known to contain polyphenol antioxidants, naturally occurring chemicals that can upregulate certain beneficial metabolic processes in mammals. The astringent blackberry root is sometimes used in herbal medicine as a treatment for diarrhea and dysentery.The related but smaller dewberry can be distinguished by the white, waxy coating on the fruits, which also usually have fewer drupelets. (Rubus caesius) is in its own section (Caesii) within the subgenus Rubus.

In some parts of the world, such as in Australia, Chile, New Zealand and the Pacific Northwest region of North America, some blackberry species, particularly Rubus armeniacus (syn. R. procerus, 'Himalaya') and Rubus laciniatus ('Evergreen') are naturalised and considered an invasive species and a serious weed.

As there is forensic evidence from the Iron Age Haraldskær Woman that she consumed blackberries some 2500 years ago, it is reasonable to conclude that blackberries have been eaten by humans over thousands