Rubus allegheniensis Porter

• En: Alleghaney blackberry, common blackberry, sow-teat blackberry
• Fr: ronce des Alléghanys, ronce alléghanienne
• Oj: odatagaagominagaawanzh

Rosaceae (Rose Family)

General: A deciduous shrub, 1-3 m tall, with biennial, erect to arching, 5-ridged or angular, reddish-purple stems (canes), often forming dense thickets. Young and mature canes are usually armed with scattered broad-based prickles, 3-10 mm long, and stalked glandular hairs.

Leaves: Alternate, palmately compound, and stalked (petiolate). Vegetative canes (primocanes) have leaves with 5 leaflets; those of the second-year flowering canes (floricanes) have 3 leaflets or a reduced, simple, lanceolate leaf. Petioles are hairy (pubescent) and bear stalked glands as well as small recurved prickles. The terminal leaflet is ovate, 6-20 cm long and 3-11 cm wide, and stalked, the petiolule 1.5-5 cm long; the base is rounded to cordate; the apex is long and narrowly pointed (attenuate to caudate). Lateral leaflets are lanceolate to ovate and smaller than the terminal leaflet; the middle pair of leaflets has shorter petiolules, while the lowest pair of leaflets is nearly sessile, with petiolules <1-4 mm long. All leaflets are green above with scattered hairs, green and velvety-pubescent beneath; margins are sharply toothed (serrate), often double-toothed (double-serrate).

Flowers: Bisexual, arranged in terminal clusters (racemes), 1-3 dm long, of up to 20 flowers. The floral axis (rachis), flower stalks (pedicels), and calyx lobes are densely glandular-pubescent with stalked glands and slender, straight to slightly curved prickles. Calyx green, with 5 ovate, acuminate lobes; petals 5, white, oblanceolate to obovate, 10-20 mm long, 4-12 mm wide; stamens numerous, spreading; pistils numerous, superior; the styles persistent in fruit. Flowers bloom in early to mid summer.

Fruit: A rounded, aggregate fruit, to 2 cm long, composed of a cluster of small drupes (an aggregate of drupelets), becoming purplish-black when mature; edible and juicy or dryish; not separating from the receptacle. Fruits mature in late summer.

Habitat and Range: Thickets, forest edges, and open and disturbed habitats, such as abandoned fields, rights-of-way, and roadsides. The common blackberry has an eastern North American range and occurs throughout southern and eastern Ontario, extending northwest to the Wawa area.

Similar Species: The smooth blackberry (Rubus canadensis) can be distinguished by its smooth, glandless stems.

Blackberry canes are similar in appearance to those of raspberries (Rubus idaeus ), but raspberries can be distinguished by their pinnately compound leaves and red aggregate fruits that separate easily from the receptacle.

Internet Images:

http://www.missouriplants.com/Whitealt/Rubus_allegheniensis_page.html
http://www.fw.vt.edu/dendro/dendrology/syllabus/factsheet.cfm?ID=139
http://www.uwgb.edu/BIODIVERSITY/herbarium/shrubs/ruball01.htm