Penstemon fruticosus
Credits
Article from Bean's Trees and Shrubs Hardy in the British Isles
Recommended citation
'Penstemon fruticosus' from the website Trees and Shrubs Online (treesandshrubsonline.
Synonyms
- Gerardia fruticosa Pursh
- Penstemon lewisii Benth.
- Penstemon crassifolius Lindl.
Editorial Note
Penstemon douglasii Hook. and its combinations Penstemon menziesii var. douglasii (Hook.) A.Gray and Penstemon fruticosus var. douglasii (Hook.) Schneid., all cited in synonymy by Bean following Gray (1886) and Schneider (1907), are referred to Penstemon davidsonii var. menziesii (D.D.Keck) Cronquist by POWO (26/6/2025).
David Douglas collected a Penstemon with small, rather thick, entire leaves in the Blue Mountains of Oregon in 1827. Names based on Douglas’s material – but with different types – were independently published in 1838 by the elder Hooker (as P. douglasii, based on Douglas’s dried specimen), and by Lindley (as P. crassifolius, based on plants raised from the seeds). Bean notes that “the Douglas introduction and other plants of a similar nature are now considered to be part of the normal variation of the species.” However, Hooker’s and Lindley’s types appear to be from different taxa, and are now referred to Penstemon davidsonii var. menziesii and Penstemon fruticosus var. fruticosus, respectively.
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.
var. scouleri (Douglas) Cronquist
Synonyms
Penstemon scouleri Douglas
Penstemon menziesii var. scouleri (Douglas) A.Gray
Penstemon fruticosus subsp. scouleri (Douglas) Pennell & D.D.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.