A shrub 5 to 8 ft high, the stems armed with stout, flattened, usually recurved prickles with a broad base, paired at the nodes; strong shoots often bristly. Leaves 3 to 5 in. long; rachis downy. Leaflets mostly five or seven, oval or ovate, usually obtuse at the apex, finely downy or glabrous above, hairy beneath, especially on the midrib and nerves, edged with simple or compound teeth. Flowers about 11⁄2 in. wide, pink, borne on long laterals, frequently over a dozen in a cluster, each subtended by a leafy bract. Pedicels glabrous or hairy, sometimes glandular. Sepals entire, finely tapered at the apex, glabrous or hairy on the back, sometimes glandular at the edge. Fruits globose or slightly elongated, 3⁄8 to 1⁄2 in. wide, contracted into a well-defined neck below the persisting erect sepals.
Native of western N. America from S. Oregon to Lower California, mainly represented in Britain by a double form. An interesting feature of this species, unusual in wild roses, is its ability to produce flowers at the end of strong seasonal shoots.
For a revision of the R. californica complex, see D. Cole in Amer. Midl. Nat., Vol. 55 (1956), pp. 211-24.
cv. ‘Plena’. – The name R. californica f. plena Rehd. is based on the semi-double form portrayed as R. californica in Willmott, The Genus Rosa, Vol. I, p. 223, t. The plant now grown as ‘Plena’, which may be a different clone, was introduced to this country by Mrs L. Fleischmann, who obtained her stock from the American firm Bobbink and Atkins of New Jersey (Graham Thomas, Shrub Roses of Today, p. 70 and photo 1). This is a very vigorous rose with semi-double flowers of a rich pink, borne in late June or July; a conspicuous feature of the buds is the long and slender tips to the sepals. Award of Merit 1958, when exhibited by Mrs Fleischmann and the John Innes Horticultural Institution.