A shrub up to 12 ft high, of graceful, pendulous habit; year-old branches with greyish-brown, non-peeling bark. Leaves broadly ovate to ovate-lanceolate, 11⁄2 to 4 in. long, 1 to 21⁄2 in. wide, coarsely and distinctly toothed or, especially on the flowering twigs, entire, with scattered hairs beneath, still fewer above. Flowers five to nine, in racemes, scentless, white, 11⁄3 in. across; petals oval; calyx smooth outside like the flower-stalk, downy at the margins, and near the apex of the lobes inside; styles divided half-way down.
Native of western N. America from British Columbia to Oregon; introduced about 1823. It is one of the most elegant and floriferous of all the taller species.
var. gordonianus (Lindl.) Jeps. P. gordonianus Lindl. – Leaves downy beneath all over the blade. Flowers (at least in Lindley’s type) up to almost 2 in. across. British Columbia to California. A handsome and very hardy variety, introduced by David Douglas in 1825, and described (as a species) from a plant raised from the seeds he sent.
P. lewisii is a variable species. The var. gordonianus and others recognised by Dr Hu, intergrade with each other and with the type. The plant described above under P. lewisii does not perfectly match the type of P. lewisii, but neither does it fit into any of the named varieties. The species seems to vary in the fragrance of its flowers.