1 1 ROSACEAE 



rather than as a species; it would then be known as R. idaeus 

 var. strigosus (Michaux) Maximowicz. 



RUBUS ALLEGHENIENSIS Porter 

 Blackberry Allegheny Blackberry 



The Allegheny Blackberry, fig. 25, is a relatively erect shrub 

 with canes that when old attain a length of 3 to 6 feet and are 

 recurved in the upper part. The lower part of the stem is 

 terete, but the upper part is angled and sparsely clothed with 

 straight, or in the inflorescence recurved, prickles. The erect, 

 angled new canes bear leaves which are either 3- or 5-foliate. 

 Petioles, leaf stalks and midribs are villous and glandular. 

 Leaflets are ovate, doubly serrate, abruptly acuminate, pilose 

 above but softly pubescent beneath, and ^ to 4 inches long. 



The flowers are borne in May in elongated racemes of 6 to 

 20 or more flowers, which extend well beyond the leaves. The 

 pedicel of each flower arises from the axil of a bract. The petals 

 are white, and the sepals are reflexed while the plant is in flower. 

 The pedicels on which the flowers stand are long and spread at 

 a wide angle from the midstalk of the racemes. Fruit begins 

 to mature in July. It is black, 1/4 to yz inch long, hemispheric, 

 and tart. 



Distribution. — The Allegheny Blackberry prefers moist, 

 rich soil and frequently occurs on cut-over woodland, in open 

 woods, and along fences and roadsides. It is perhaps the com- 

 monest blackberry in Illinois and grows everywhere in the 

 state. It is the original wild form from which many of the 

 cultivated blackberries have been selected. 



RUBUS CANADENSIS Linriaeus 



Wild Blackberry 



This Wild Blackberry, fig. 25, is a shrub with erect stems 

 which reach a length of 3 to 12 feet and are grooved, round 

 angled, and glabrous. Sometimes they are unarmed or are pro- 

 vided with a few weak, straight prickles. The leaves on new 

 shoots are 5-foliate, those on old shoots 3-foliate. The thin, 

 dark green leaflets are glabrous or nearly so, sharply serrate, 

 abruptly long-acuminate at the tip, rounded or subcordate at 

 the base, and 2 to 6 inches long. Leaflets on flowering branches 



