UW Burke Herbarium species comparison

Leaves trifoliate, the leaflets ovate, nearly glabrous, doubly serrate, the terminal one 4-9 cm. long, the others smaller, often lobed.

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 1-2 on short leafy branches;

calyx pubescent, the 5 lobes ovate-lanceolate, pointed, spreading, 9-15 mm. long;

petals 5, purplish-red, obovate-elliptic, half again as long as the sepals;

stamens 75-100;

pistils numerous.

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 yellow to reddish, weakly coherent, coming free from the receptacle.

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