''Rubus strigosus'', the American red raspberry or American raspberry, is a species of ''

Rubus ''Rubus'' is a large and diverse genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae, most commonly known as brambles. Fruits of various species are known as raspberries, blackberries, dewberries, and bristleberries. ...

'' native to much of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. It was often treated as a

variety Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the closely related Eurasian ''

Rubus idaeus ''Rubus idaeus'' (raspberry, also called red raspberry or occasionally European red raspberry to distinguish it from other raspberry species) is a red-fruited species of ''Rubus'' native to Europe and northern Asia and commonly cultivated in oth ...

'' (red raspberry or European red raspberry), but is now more commonly treated as a distinct species. Many of the commercial raspberry

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

s grown for their fruit derive from

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two diff ...

s between ''R. strigosus'' and ''R. idaeus''; see

Raspberry The raspberry is the edible fruit of several plant species in the genus ''Rubus'' of the Rosaceae, rose family, most of which are in the subgenus ''Rubus#Modern classification, Idaeobatus''. The name also applies to these plants themselves. Ras ...

for more details.

Classification

Botanists have long debated the taxonomic treatment of the Eurasian and American red raspberries, with some viewing all of these plants as members of a single,

circumboreal The Circumboreal Region in phytogeography is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan. It is the largest floristic region in ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

''Rubus idaeus,'' and others recognizing two (or more) species within this group.Fernald doubted this distinction, but Bailey and many other authors rely on it. The two species share many similarities, and probably recently diverged from a common ancestor, leading to differences in taxonomic interpretation, particularly regarding the more intermediate eastern Asian plants. A common current treatment, followed here, is to classify the North American red raspberries as ''Rubus strigosus,'' and include only the Eurasian plants in ''Rubus idaeus.'' When the species are combined, as done in some recent publications, the Eurasian plants are ''Rubus idaeus'' ssp. ''idaeus'' (or ''Rubus idaeus'' var. ''idaeus),'' and the American plants ''R. idaeus'' ssp. ''strigosus'' (or ''R. idaeus'' var. ''strigosus).'' Different interpretations are also sometimes made regarding placement of various eastern Asian populations of this group, by some considered to represent additional varieties or subspecies, if not different species altogether. The most distinctive physical difference among these plants is usual presence of

gland A gland is a Cell (biology), cell or an Organ (biology), organ in an animal's body that produces and secretes different substances that the organism needs, either into the bloodstream or into a body cavity or outer surface. A gland may also funct ...

-tipped hairs on first-year canes, petioles, pedicels, and calyces of ''R. strigosus,'' lacking in ''R. idaeus.''

Distribution

''Rubus strigosus,'' as treated here, is widely distributed in North America, particularly the more boreal regions. Some authors also treat various raspberries in eastern Asia, east from the

Altai Mountain Range The Altai Mountains (), also spelled Altay Mountains, are a mountain range in Central and East Asia, where Russia, China, Mongolia, and Kazakhstan converge, and where the rivers Irtysh and Ob have their headwaters. The massif merges with th ...

in Mongolia to

Manchuria Manchuria is a historical region in northeast Asia encompassing the entirety of present-day northeast China and parts of the modern-day Russian Far East south of the Uda (Khabarovsk Krai), Uda River and the Tukuringra-Dzhagdy Ranges. The exact ...

and Japan in this taxon (where it is suggested to have originated along with a great deal of the North American flora), but others include all Asian raspberries in ''R. idaeus''. with the Eurasian plants being ''Rubus idaeus'' ssp. (or var.) ''idaeus''.

Description

''R. strigosus'' is a

perennial plant In horticulture, the term perennial (''wikt:per-#Prefix, per-'' + ''wikt:-ennial#Suffix, -ennial'', "through the year") is used to differentiate a plant from shorter-lived annual plant, annuals and biennial plant, biennials. It has thus been d ...

which bears

biennial Biennial means (an event) lasting for two years or occurring every two years. The related term biennium is used in reference to a period of two years. In particular, it can refer to: * Biennial plant, a plant which blooms in its second year and t ...

stems ("canes") from the perennial root system. In its first year, a new stem grows vigorously to its full height of 0.5–2 m, unbranched, and bearing large pinnate

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

with three or five (rarely seven) leaflets; normally it does not produce any flowers. In its second year, the stem does not grow taller, but produces several side shoots, which bear smaller leaves with three leaflets. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are produced in late spring on short

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

s on the tips of these side shoots, each flower with five white

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s long. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is diameter, red, edible, sweet but tart-flavored, produced in summer or early autumn; in

botanical Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

terminology, it is not a

berry A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit although many pips or seeds may be present. Common examples of berries in the cul ...

at all, but an

aggregate fruit A raspberry_beetle.html" ;"title="raspberry fruit (shown with a raspberry beetle">raspberry fruit (shown with a raspberry beetle larva) is an aggregate fruit, an aggregate of drupelets. image:Aquilegia vulgaris 004.JPG, The fruit of an ''Aquilegi ...

of numerous

drupelet In botany, a drupe (or stone fruit) is a type of fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pip'' (UK), ''pit'' (US), ''stone'', or ''pyrena'') of hardened endocarp with a seed ...

s around a central core.

References

{{Taxonbar, from=Q210156 strigosus Berries Flora of Western Canada Flora of the Western United States Flora of the Rocky Mountains Flora of the North-Central United States Flora of the Great Lakes region (North America) Flora of Eastern Canada Flora of the Northeastern United States Flora of Idaho Flora of California Garden plants of North America Vines Flora of Northern America Flora without expected TNC conservation status