Rubus

Rubus
Rubus fruticosus
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Rosales
Family:	Rosaceae
Subfamily:	Rosoideae
Tribe:	Rubeae[1]
Genus:	Rubus L.
Species
See text.

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 also common in the genus. The Rubus fruit, sometimes called a bramble fruit, is an aggregate of drupelets.

The blackberries, as well as various other Rubus species with mounding or rambling growth habits, are often called brambles. However, this name is not used for those like the raspberry that grow as upright canes, or for trailing or prostrate species such as most dewberries, or various low-growing boreal, arctic, or alpine species.

The genus Rubus is believed to have existed since at least 23.7 to 36.6 million years ago.^[2]

Examples of the hundreds, if not thousands, of species of Rubus include:

• Rubus allegheniensis – Allegheny Blackberry
• Rubus arcticus – Arctic Raspberry
• Rubus armeniacus – Himalayan Blackberry
• Rubus caesius – European Dewberry
• Rubus calycinoides – Creeping Raspberry
• Rubus canadensis – Canadian Blackberry
• Rubus chamaemorus – Cloudberry
• Rubus coreanus - Bokbunja
• Rubus cuneifolius – Sand Blackberry
• Rubus fruticosus agg. – Blackberry
• Rubus idaeus – European Red Raspberry
• Rubus laciniatus - Cutleaf Evergreen Blackberry
• Rubus leucodermis – Whitebark Raspberry or Western Raspberry
• Rubus occidentalis – Black Raspberry
• Rubus odoratus – Flowering Raspberry
• Rubus parviflorus – Thimbleberry
• Rubus pensilvanicus – Pennsylvania Blackberry
• Rubus phoenicolasius – Wineberry
• Rubus saxatilis – Stone Bramble
• Rubus spectabilis – Salmonberry
• Rubus strigosus – American Red Raspberry
• Rubus trifidus - Japanese Blackberry
• Rubus ursinus – Trailing Blackberry

The genus also includes numerous hybrids, both natural and bred by man, such as the Loganberry (Rubus × loganobaccus).

See also: List of Lepidoptera that feed on Rubus

Scientific classification

The genus Rubus is a very complex one, particularly 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.

Rubus species have a basic chromosome number of seven. Polyploidy from the diploid (14 chromosomes) to the tetradecaploid (98 chromosomes) is exhibited.

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 R. strigosus both recognized; if these species are combined, then the older name R. idaeus has priority for the broader species.)

Molecular data has backed up classifications based on geography and chromosome number, but following morphological data such as the structure of the leaves and stems does not appear to produce a phylogenetic classification.^[3]

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 there are many more species not mentioned here.

A sign near this bush labeled it as a Rubus calycinoides

R. odoratus

R. saxatilis

Leaves, R. idaeus

Flower, R. fruticosus

R. laciniatus

R. spectabilis

R. rosifolius

References

1. ^ "Rubus". Germplasm Resources Information Network. United States Department of Agriculture. 2007-10-05. http://www.ars-grin.gov/cgi-bin/npgs/html/genus.pl?10574. Retrieved 2009-02-17. 
2. ^ Rosales
3. ^ Lawrence A. Alice and Christopher S. Campbell (1999). "Phylogeny of Rubus (rosaceae) based on nuclear ribosomal DNA internal transcribed spacer region sequences". American Journal of Botany 86: 81–97. doi:10.2307/2656957. http://www.amjbot.org/cgi/content/full/86/1/81. 

External links

Wikimedia Commons has media related to: Rubus

• WKU Rubus website