Rubus is a large and diverse genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae, most commonly known as brambles.
Most of these plants have woody stems with prickles like roses; spines, bristles, and gland-tipped hairs are also common in the genus. The Rubus fruit, sometimes called a bramble fruit, is an Aggregate fruit of . The term cane fruit or cane berry applies to any Rubus species or hybrid which is commonly grown with supports such as wires or canes, including raspberries, blackberries, and hybrids such as loganberry, boysenberry, marionberry and tayberry.
Description
Bramble bushes typically grow as
(though a few are
Herbaceous plant), with their stems being typically covered in sharp prickles.
They grow long, arching shoots that readily root upon contact with soil,
and form a soil
rootstock from which new shoots grow in the spring.
The leaves are either
evergreen or
deciduous, and
Simple leaf,
lobed, or
Compound leaf.
The shoots typically do not flower or set
fruit until the second year of growth (i.e. they are
Biennial plant).
The rootstock is
Perennial plant.
Most
species are
plant sexuality with male and female parts being present on the same flower.
Bramble fruits are aggregate fruits formed from smaller units called
.
Around 60-70% of species of Rubus are Polyploidy (having more than two copies of each chromosome), with species ranging in ploidy from diploid (2x, with 14 chromosomes
Taxonomy
Modern classification
Rubus is the only genus in the tribe Rubeae.
Rubus is very complex, particularly within the blackberry/dewberry subgenus ( Rubus), with polyploidy, hybridization, and facultative apomixis apparently all frequently occurring, making species classification of the great variation in the subgenus one of the grand challenges of systematic botany. In publications between 1910 and 1914, German botanist Wilhelm Olbers Focke attempted to organize the genus into 12 subgenera, a classification system that since became widely accepted, though modern genetic studies have found that many of these subgenera are not monophyletic.
Some treatments have recognized dozens of species each for what other, comparably qualified botanists have considered single, more variable species. On the other hand, species in the other Rubus subgenera (such as the raspberries) are generally distinct, or else involved in more routine one-or-a-few taxonomic debates, such as whether the European and American red raspberries are better treated as one species or two (in this case, the two-species view is followed here, with Rubus idaeus and Rubus strigosus both recognized; if these species are combined, then the older name R. idaeus has priority for the broader species).
The classification presented below recognizes 13 subgenera within Rubus, with the largest subgenus ( Rubus) in turn divided into 12 sections. Representative examples are presented, but many more species are not mentioned here. A comprehensive 2019 study found subgenera Orobatus and Anoplobatus to be monophyletic, while all other subgenera to be paraphyletic or polyphyletic.
Phylogeny
The genus has a likely North American origin,
with fossils known from the
Eocene-aged Florissant Formation of Colorado, around 34 million years old.
expanded into Eurasia, South America, and Oceania during the
Miocene.
seeds from the early
Miocene of
Rubus have been found in the
Czech Republic part of the
Zittau Basin.
[Acta Palaeobotanica – 43(1): 9-49, January 2003 – Early Miocene carpological material from the Czech part of the Zittau Basin – Vasilis Teodoridis] Many fossil fruits of †
Rubus laticostatus, †
Rubus microspermus and †
Rubus semirotundatus have been extracted from bore hole samples of the
Middle Miocene fresh water deposits in
Nowy Sacz Basin,
West Carpathians,
Poland.
[Łańcucka-Środoniowa M.: Macroscopic plant remains from the freshwater Miocene of the Nowy Sącz Basin (West Carpathians, Poland) Szczątki. Acta Palaeobotanica 1979 20 (1): 3-117.]
Molecular data have backed up classifications based on geography and chromosome number, but following Plant morphology data, such as the structure of the leaves and stems, do not appear to produce a phylogenetic classification.
Species
Better-known species of
Rubus include:
A more complete subdivision is as follows:
Hybrid berries
The term "hybrid berry" is often used collectively for those fruits in the genus
Rubus which have been developed mainly in the U.S. and U.K. in the last 130 years. As
Rubus species readily interbreed and are
(able to set seed without fertilisation), the parentage of these plants is often highly complex, but is generally agreed to include cultivars of blackberries (
R. ursinus,
R. fruticosus) and raspberries (
R. idaeus). The British National Collection of
Rubus stands at over 200 species and, although not within the scope of the National Collection, also hold many cultivars.
[ National Collection of Rubus Species, Houghton, England, United Kingdom www.rubusspecies.com]
The hybrid berries include:-
-
loganberry (California, U.S., 1883) R. × loganobaccus, a spontaneous hybrid between R. ursinus 'Aughinbaugh' and R. idaeus 'Red Antwerp'
-
boysenberry (U.S., 1920s) a hybrid between R. idaeus and R. × loganobaccus
-
nectarberry Suspected variant of boysenberry, a hybrid between R. idaeus and R. × loganobaccus
-
olallieberry (U.S., 1930s) a hybrid between the loganberry and youngberry, themselves both hybrid berries
-
veitchberry (Europe, 1930s) a hybrid between R. fruticosus and R. idaeus
-
skellyberry (Texas, U.S., 2000s), a hybrid between R. invisus and R. phoenicolasius
-
marionberry (1956) now thought to be a blackberry cultivar R. 'Marion'
-
silvanberry, R. 'Silvan', a hybrid between R. 'Marion' and the boysenberry
-
tayberry (Dundee, Scotland, 1979), another blackberry/raspberry hybrid
-
tummelberry, R. 'Tummel', from the same Scottish breeding programme as the tayberry
-
hildaberry (1980s), a tayberry/boysenberry hybrid discovered by an amateur grower
-
youngberry, a complex hybrid of raspberries, blackberries, and dewberries
Etymology
The generic name means blackberry in
Latin and was derived from the word
ruber, meaning "red".
The blackberries, as well as various other Rubus species with mounding or rambling growth habits, are often called .
See also
-
Mulberry, an unrelated deciduous tree with similar looking fruit
External links
-
Rubus at the Western Kentucky University
