|Berries and leaves of Rubus flagellaris|
Rubus flagellaris, the northern dewberry, also known as the common dewberry, is a perennial subshrub species of the Rosaceae or rose family. It can exist as a woody vine or low growing shrub and is distributed from Nebraska to mostly all of the states to the east of it in the United States. It is also found in central and eastern territories and provinces of Canada as well. It grows in a host of habitats ranging from dry savannas to deciduous forests. It also produces a dark purple drupe that when fully ripened has a tart-sweet flavor.
Individuals of this species are composed of low-growing stems that range from eight to fifteen feet long and flowering stems that can grow up to four feet high. The young stems are green with a scattered arrangement of hairy prickles. The old stems are brown, woody and have hard prickles in comparison to the young stem. Sometimes the tips of the young stems root into the ground and form vegetative offsets.
It has an alternate compound leaf arrangement, with mostly three, but sometimes five leaflets attached. The margins of the leaves are serrated while the leaves show a palmate venation. Each leaflet is approximately three inches long and one inch wide, with an ovate shape to each. The leaflets are green on top, but pale green on the underside. One leaflet of a set is connected by a petiole to the stem while the other leaflets in the set are connected to that terminal leaflet. The roots of the northern dewberry consist of a woody taproot.
Flowers of R. flagellaris are white and contain five petals. The flowers are hermaphrodites and have both female and male sex organs. There are five sepals, green in appearance, lanceolate in shape. The ovaries exhibit a superior position relative to the sepals and petals. Several stamen surround a cluster of carpels. The most active growth occurs from mid-spring to early summer. The flowers would then open up at day time, but close up at night time.
Once the flowers of the northern dewberry are fertilized, drupes soon grow and replace each flower. The drupes are a dark-purplish color and range from ½ inch to one inch in diameter. Once the fruit has fully ripened a notable tart-sweet flavor is obtained. Many animals such as raccoons, fox squirrels, eastern chipmunks, white-footed mice and other mammals eat the drupes and aid in the dispersal of the shrub.
Distribution and habitat
Rubus flagellaris is native to the middle and eastern United States from Texas, Oklahoma, Kansas, Nebraska to the eastern coast. R. flagellaris is also native to areas in Canada such as Ontario, Quebec, New Brunswick and Nova Scotia. It grows on dry soils, bogs, soft soils and wooded soils. This species is actually especially adapted to coarse textured soils (such as sandy soils), fine textured soils (such as loamy soils) and medium textured soils (such as clay-textured soils). R. flagellaris grows in a wide range of habitats including mesic to dry savannas and sandy savannas, abandoned fields, meadows in wooded areas and woodland borders. The species has its most active growth from the spring to the summer. It is adapted to a precipitation zone that ranges from 15 to 40 inches/yr, tolerate a soil pH ranging from 5.0 to 7.0 and can grow in temperatures as low as -23 °F. [Can survive, surely. Actual growth must hapen at much warmer temps.] This species also has a low tolerance to drought conditions as compared to other species with the same growth habit from the same geographical region. It has no salinity tolerance and this species has an intermediate shade tolerance as compared to other species with the same growth habit from the same geographical region.
When occasional wildfires burn down tall woody trees surrounding R. flagellaris, the resulting burning has a positive effect on population growth for the subshrub species. Other research has also shown that occasional fires are beneficial to the population growth of R. flagellaris. The flowers of this species are excellent at attracting a large number of native bees (with a fragrant nectar) as well as providing nesting materials and structures for the native bees. Some of the bee species that interact with R. flagellaris are mason bees (of the genus Osmia), leaf-cutting bees, cuckoo bees (of the subfamily Nomadine), and miner bees. These bees help to pollinate the flowers of the northern dewberry. Other insects that interact with the northern dewberry to help pollinate it are Siphonopora rubi (blackberry aphid), Metallus rubi (blackberry leafminer), Agrilus ruficollis (red-necked cane borer) and Edwardsiana rosae (rose leafhopper). The R. flagellaris flowers have also been seen to be a preferential source of nectar for the Karner blue, an endangered species of blue butterfly found in the U.S. Midwest and northeastern areas of the continent. R. flagellaris also has a high tolerance to hedging from livestock or wildlife.
- Natural Resources Conservation Service. "Rubus flagellaris Willd. northern dewberry". Plants Database. United States Department of Agriculture (USDA). Retrieved April 29, 2012.
- Hilty, John. "Common Dewberry". Wildflowers of Illinois in Savannas & Thickets. Retrieved April 29, 2012.
- Seiler, John; Jensen, Edward; Niemiera, Alex; Peterson, John (2011). "dewberry Rosaceae Rubus flagellaris Willd.". Virginia Tech Department of Forest Resources and Environmental Conservation. Retrieved April 30, 2012.
- "Family Rosaceae Rubus flagellaris Willd". Robert W. Freckmann Herbarium. Retrieved April 30, 2012.
- >"Rubus flagellaris - Willd.". Plants for a Future. Retrieved April 30, 2012.
- Taft, John B. (December 2005). "Fire Effects on Structure, Composition, and Diversity in a South-Central Illinois Flatwoods Remnant". Castanea 70 (4): 298–313. doi:10.2179/0008-7475(2005)070[0298:FEOSCA]2.0.CO;2. ISSN 0008-7475. JSTOR 4034296.
- ‘’Lary Bird Johnson Wildflower Center’’, Rubus flagellaris Willd, April 30, 2012
- Grundel, Ralph; Pavlovic, Noel B.; Sulzman, Christina L (2000). "Nectar plant selection by the Karner blue butterfly (Lycaeides melissa samuelis) at the Indiana Dunes National Lakeshore". The American Midland Naturalist 144 (1): 1–10. doi:10.1674/0003-0031(2000)144[0001:NPSBTK]2.0.CO;2. ISSN 0003-0031. JSTOR 3083005.