R. strigosus is a perennial plant which bears biennial stems ("canes") from the perennial root system. In its first year, a new stem grows vigorously to its full height of 0.5–2 m, unbranched, and bearing large pinnate leaves with three or five (rarely seven) leaflets; normally it does not produce any flowers. In its second year, the stem does not grow taller, but produces several side shoots, which bear smaller leaves with three leaflets.

The flowers are produced in late spring on short racemes on the tips of these side shoots, each flower with five white petals 4–7 mm (0.16–0.28 in) long. The fruit is 1–1.2 cm (0.39–0.47 in) diameter, red, edible, sweet but tart-flavored, produced in summer or early autumn; in botanical terminology, it is not a berry at all, but an aggregate fruit of numerous drupelets around a central core.