American Red Raspberry is a native perennial shrubby bramble that grows up to 7 feet high that produces biennial canes (stems) that are erect to drooping, but first year canes usually do not root at the tips if they touch ground nor do they usually branch. Young stems are covered with fine straight glandular prickles with narrow bases.
Leaves are 3 to 7 parted with teeth. Occasionally there may be a 3-lobed simple leaf. New canes will typically have the 5 to 7-parted leaf, second year canes the 3 to 5-parted leaf. The terminal leaflet has a short stalk, the lateral leaflets are usually not stalked (sessile). The upper side is light to medium green and underside is much paler, almost white due to soft fuzzy hair. The leaf stalk also has fine glandular hair.
The inflorescence is a cyme (an umbel like cluster) of 2 to 5 flowers that occurs on new short side branches that grow from the second year cane, or occasionally, springs from the leaf axils. First year canes are usually vegetative only, but may be developed by the nursery trade to produce fall fruit the first year and then fruit again the second year. Stalks of the flowers in the clusters are densely bristly hairy.
Flowers are 5-parted with white to greenish-white petals that are broad at the tips; the 5 green pointed sepals that have velvety hair. Petals are slightly shorter than the sepals and fall away quickly. The center of the flower is a mass of carpels, each with a style, that will form the fruit. These are surrounded by a large number of stamens that have yellow anthers.
Fruit: Fertile flowers produce an edible berry composed of a number of drupelets that each contain a seed. When picked, the drupelets separate from the core stem (the torus) easily, forming a hollow base. Fruit is red at maturity.
Habitat: Red Raspberry grows in a variety of soils, from woods to fields to roadsides, needing at least partial sun with moist to dry moisture conditions. It will fruit only with adequate sun and adequate early summer moisture. The root system is a branching taproot.
Names: The genus name Rubus is the Latin name for bramble and idaeus refers to Mt. Ida in Crete. The species grows from Northern Europe to northwest Asia. The species growing in North America is closely related and usually regarded as Rubus idaeus var. strigosus. The variety name strigosus, means 'with stiff bristles' and this species has plenty. That species is a native of North America that is a valuable plant for wildlife. It can be propagated from the seeds and are best sown in early fall in a cold frame. Cuttings can propagated from the hardwood.
The accepted author of the plant classification of the main species, 'L.', refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. There are two authors for the variety; first ‘Michx.’ refers to Andre Michaux (1746-1802), French botanist who made many exploring expeditions in the U.S. collecting and cataloging many species. Two important works of his are the Histoire des chênes de l'Amérique septentrionale (1801 - Oaks of North America), and the Flora Boreali-Americana (2 vols., 1803). His son Francois, traveled with him and the father’s notes were later used for the 3-volume North American Sylva, for which Thomas Nuttall provided some supplements. His work was amended by ‘Focke’ which refers to Wihelm Olbers Focke (1834-1922) German doctor and botanist who published a significant book on plant breeding in 1881, Die Pflanzen-Mischinge.
Comparisons: Differences between R. idaeus and R. occidentalis, the Black Raspberry, other than the fruit color are that R. idaeus does not typically root at the tips of new canes, the sepals are not much longer than the petals and the presence of glandular hair. These other examples of Rubus are or have been in the Garden: Thimbleberry, R. parviflorus; Dewberry, R. flagellaris; Blackberry, R. allegheniensis. and Purple Flowering Raspberry, R. odoratus.
Above: Stalks in the cluster are densely bristly hairy. The red berries separate cleanly from their stem when mature.
Leaves: New canes will typically have the 5 to 7-parted leaf (1st photo), second year flowering canes the 3 to 5-parted leaf (2nd photo).
Below: Young canes have fine, thin prickles with glandular bases.
Notes: American Red Raspberry is indigenous to the Garden area. Eloise Butler catalogued it on April 29, 1907. In her day she knew it as Rubus idaeus var aculeatissimus, now reclassified to Rubus idaeus L. var. strigosus. This species is considered by the MN DNR and the U of M Herbarium to be the native plant in Minnesota and is widespread, absent only in some of the southern counties and a few in the NW. In her 1926 article Shrubs in the Wild Garden she noted it was on of the four most abundant under-shrubs. She also stated that it could be denominated as "weedy" and was grubbed out continually. It is found throughout North America except for the gulf coast states of the U.S. If the European species of Rubus idaeus (gland-less canes) is found growing it is considered a cultivated escapee.
Species: The Minnesota DNR lists 38 species of Rubus in its county location records. The U of M Herbarium makes a list of 54 species that are present or have been reported at one time to be present and gives this disclaimer about the descriptions of the Rubus species: "Rubus is a a very complex taxon with much hybridization, polyploidization, and apomixis occurring within taxa. The group as a whole is difficult to separate into species (especially since both first and second year growth are needed for identification) and there has been much disagreement regarding species distinctions, particularly when statewide or regional populations are considered in the absence of the wider distributions of the species." (Ref. #28C)
Uses and medicinal lore: Besides producing edible fruit that has long been used to make preserves and jellies, the American Red Raspberry has some interesting medicinal uses. Densmore (Ref. #5) reports that the Minnesota Chippewa used the inner bark of the root to treat diseases of the eye, particularly cataract. A two step process was involved. First the inner bark of a wild rose root was used, and then followed by taking the scrapings of the second (inner) layer of the root of the raspberry, in both cases - one following the other-, placing them in a soft cloth, soaking it in warm water and then squeezing the liquid out of the cloth and over the eye - done 3x per day. Unless the cataract was well advanced, this was said to produce improvement. Both Hutchins (Ref. #12) and Harrington (Ref. #9) report that the leaves of the wild raspberry were used to make a tea, either by themselves or in combination with other ingredients, that could be drank during pregnancy, but only in limited amounts to avoid side effects.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"