1. Rubus arizonensis Focke. Arizona dewberry. 



Stem biennial, trailing, terete, glabrous, 1-6 m. long, armed with short recurved 

 flattened prickles, yellowish-green; leaves of the primocanes 5-foliolate; stipules sub- 

 ulate, adnate at the base, about 5 mm. long; petioles, petiolules, and midveins 

 sparingly pubescent, armed with strongly flattened recurved short prickles; termi- 

 nal leaflet ovate, irregularly dentate-serrate, acute at the apex, rounded at the 

 base, 4-5 cm. long, thin, sparingly pilose above, more or less softly pubescent 

 beneath, its petiolule about 2 cm. long; lateral leaflets ovate, short-petioluled, 

 the outermost lanceolate to oblanceolate, sessile, 2-3 cm. long; floral branches 

 5-10 cm. long; leaves 1- to 5-foliolate, 1-4 cm. long, more pubescent and 

 more sharply serrate than those of the primocanes; inflorescence 1- to 5-flowered, 

 corymbiform, leafy-bracted, villous and armed with recurved prickles; sepals 

 ovate, mucronate, 5-6 mm. long, villous-tomentose on both sides; petals white, 

 broadly obovate or oval, 8-9 mm. long; fruit globose, 10-12 mm. broad; drupe- 

 lets 12 to 25, large and juicy; putamen strongly reticulate, 3 mm. long. R. oligos- 

 permus Thornb. 



In wet soil along streams, often in partial shade, Ariz, (widespread), Mar.-May; 

 also Son., S.L.P., Jal. and Dgo. 



Because of its trailing habit this plant is considered to be a good ground cover 

 that protects the soil against erosion. 



2. Rubus louisianus Berger. 



Erect high-arching and stiffish glandless bramble to 5 m. high; canes sharply 

 angled and deeply furrowed, downy when young, eventually glabrous, green or 

 greenish-brown, adorned along the angles with scattered straight or curved 

 prickles; stipules subulate, ciliate; primocane leaflets 5, narrowly lanceolate to 

 oblanceolate, rather long-pointed at apex and somewhat narrowed toward the 

 base, bright-dull-green above, paler and sparsely soft-pubescent beneath, rather 

 regularly and sharply simply or doubly serrate; petiole rather stout, like the 

 petiolules pubescent or villous and with scattered curved prickles that extend to 

 the midveins; floricane leaves in threes or with the upper one simple and ovate- 

 deltoid, similar to but smaller than those of the primocanes, the terminal leaflet 

 2 to 3 times as long as wide; fruiting racemes pubescent, with 4 to 15 erect 

 pedicels that are pubescent and provided with a few curved prickles; flowers 

 rather large; calyx pubescent, the ovate-deltoid lobes tomentose inside; petals 

 white, oblong-elliptic to obtusely oblanceolate or obovate, 6-15 mm. long, 3.5-10 

 mm. wide; fruit oblong-oval, with numerous small drupelets, whitish, sweet. R. 

 texanus Bailey, R. ramifer Bailey, R. arvensis Bailey, R. abundiflorus Bailey, R. 

 argutus of auth. 



In damp and sandy thickets, pastures and wet lowland areas, and along fence- 

 rows in s.e. Okla. and e. Tex., Apr.; from Okla. and Tex. to S. C, n. to Md. 

 and Va. 



3. Rubus oklahomus Bailey. 



Upright but arching very prickly glandless bramble to 2 m. high, with long 

 weak horizontal or depressed branches some of which tip-root; canes terete but 

 sometimes angular; prickles straight or curved, 3-6 mm. long, broad-based; 

 primocane leaflets 3 or 5, broadly oval or the lower lateral pair rhombic, essen- 

 tially obtuse at apex, rounded or expanded at base, about 7 cm. long and 4 cm. 

 wide or more, thinly pubescent above, somewhat grayish and densely to sparsely 

 soft-pubescent beneath, the margins dentate with obtuse-apiculate teeth; floricane 

 leaflets much smaller but otherwise similar to those of the primocanes, the upper 

 ones in the flower cluster sometimes simple; flowers 3 to 5, large, showy, project- 

 ing on short laterals that are leafy at base, the ascending pedicels pubescent and 

 armed; calyx lobes very broad, apiculate or sometimes with foliaceous tips, 



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