May Appeal 2026
Please help keep TSO growing!
IDS Trees and Shrubs Online has become a fundamental source of reliable information about cultivated woody plants, freely available to everyone, everywhere. We hope you find it useful.
For the first time we are asking our users if you could support us.
If everyone who uses TSO during May 2026 gives just £10, we would cover our costs for a whole year, enabling us to accelerate our work.
Penstemon cardwellii
Credits
New article for Trees and Shrubs Online.
Recommended citation
'Penstemon cardwellii' from the website Trees and Shrubs Online (treesandshrubsonline.
Synonyms
- Penstemon fruticosus var. cardwellii (Howell) Krautter
- Penstemon 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.