Penstemon fruticosus (Pursh) Greene
Synonyms: Gerardia fruticosa Pursh; P. douglasii Hook.; P. menziesii var. douglasii (Hook.) A. Gr.; P. fruticosus var. douglasii (Hook.) Schneid.; P. lewisii Benth.; P. crassifolius Lindl.
An erect subshrub with glabrous or slightly downy stems, 6 in. to 2 ft high. Leaves variable in shape from obovate to elliptic-oblong or lanceolate, acute or obtuse at the apex, entire or saw-toothed, shortly stalked, up to 21⁄4 in. long and 5⁄8 in. wide, those at the base of the flowering shoots smaller than on the sterile shoots. Flowers arranged oppositely in short racemes, the main axis and pedicels glandular-hairy. Calyx-lobes glandular-hairy, lanceolate to lanceolate-ovate, acute to acuminate at the apex. Corolla lavender or light purple, funnel-shaped, two-lipped, the upper lip two-lobed, the lower three-lobed and hairy, 11⁄4 to 13⁄4 in. long. Stamens not exserted from the mouth of the corolla; anthers densely woolly.
Native of western N. America from southern British Columbia to Oregon, east to Montana and Wyoming; discovered by Lewis and Clark during their pioneering overland journey to the Pacific and back in 1803-6. David Douglas collected a specimen in the Blue Mountains of Oregon in 1827 and also introduced it to cultivation. The form he found had small, rather thick, entire leaves and was given specific rank as P. douglasii by the elder Hooker and as P. crassifolius by Lindley; the two names were published in the same year, the former based on the specimen he collected, the latter on plants raised from his seeds. The Douglas introduction and other plants of a similar nature are now considered to be part of the normal variation of the species.
var. scouleri (Lindl.) Cronquist P. scouleri Lindl.; P. menziesii var. scouleri (Lindl.) A. Gr.; P. fruticosus subsp. scouleri (Lindl.) Pennel & Keck – P. fruticosus is mainly represented in cultivation by this variety, which really differs from the typical state of the species only in its relatively narrower leaves, which are 1 to 2 in. long but never more than 1⁄4 in. wide; they are always finely toothed, except for the smaller basal leaves of the shoot, but the toothing is irregular and not always conspicuous. Bot. Mag., t. 6834.
This variety occurs within the area of the typical state of the species, but has a more restricted distribution. It was discovered by Douglas on the Columbia River near the Kettle Falls and introduced by him in 1828. It is hardy in a sunny position in well-drained soil and flowers in May and June. There are white- and pink-flowered forms in cultivation.
The plant portrayed in New Flora and Sylva, Vol. 3, fig. 96, as P. lyallii and discussed on p. 265 of that issue, is really a form of P. fruticosus var. scouleri. The true P. lyallii is a much taller plant and scarcely shrubby.
P. barretiae A. Gray – An ally of P. fruticosus, but quite distinct. It is an erect subshrub 1 to 2 ft high, with glabrous leaves and stems. Leaves on the sterile shoots and at the base of the flowering stems 11⁄4 to 3 in. long and up to 1 in. wide, tapered at the base into an indistinct petiole, entire or faintly toothed, rather thick and distinctly glaucous; leaves at the base of the flowering stems shorter and relatively broader, sessile. Flowers in racemes, or sometimes the peduncles two-flowered. Calyx about 1⁄4 in. long, the sepals ovate. Corolla lilac-purple, about 11⁄2 in. long. This species was discovered by a Mrs Barret and described in 1886. It has a limited distribution in the Cascade mountains, in Klickitat Co., Washington, north of the Columbia River, and in Mount Hood and Wasco Cos., Oregon, to the south of it. It was in cultivation in Britain as early as 1889 but may not have been in cultivation continuously since then. Plants raised at Kew in the 1930s from seeds received from commercial sources in California and British Columbia were not the true species but forms of P. fruticosus. But J. Elliott had what seems to have been the true species (see Gard. Chron., Vol. 120 (1946), p. 135 and fig. 63).
P. cardwellii Howell P. fruticosus var. cardwellii (Howell) Krautter; P. fruticosus subsp. cardwellii (Howell) Piper – Very closely allied to P. fruticosus, differing in the always toothed leaves obtuse or rounded at the apex, and the darker, sometimes red-purple flowers. It occurs in Oregon on the western side of the Cascade mountains and in the coastal range, and extends into S.W. Oregon. It was introduced to Kew in the 1930s by means of seeds received from Lester Rowntree of California.