UW Burke Herbarium species comparison

Leaf blades 3-6 cm. long, bright green and shining, glabrous, mostly simple, cordate-ovate, to 3-lobed, the margins dentate-serrate;

petioles with curved prickles.

Leaves alternate, partially evergreen, 3- to 5-foliate;

stipules lanceolate, 5-10 mm. long;

leaflets ovate to rotund-ovate, acuminate, 5-10 cm. long, doubly serrate, green and glabrous above, paler and pubescent beneath.

Flowers single or in pairs in the leaf axils;

calyx lobes 5, ovate-lanceolate, pointed, 6-9 mm. long, reflexed, usually purplish;

petals inconspicuous, pink to dull purple, narrowly elliptic, somewhat longer than the sepals;

stamens about 15, filaments slender, purplish;

pistils 4-9, pubescent.

Flowers numerous in flat-topped panicles, hairy and stipitate-glandular;

calyx white-woolly, the 5 lobes reflexed, lanceolate, acuminate, up to 1 cm. long;

petals 5, white, pinkish tinged, 10-15 mm. long;

stamens at least 75;

pistils numerous, styles glabrous.

Drupelets large, red;

seeds 3-4 mm. long, wrinkled.

Drupelets coherent, and with the receptacle forming a globular blackberry about 1.5 cm. thick.