Frangula purshiana subsp. purshiana

Endemic
Treatment appears in FNA Volume 12. Treatment on page 57.

Plants 1–12 m, usually treelike. Twigs red to brown, glabrescent. Leaves deciduous (often persistent on seedlings and small saplings); blade widely oblong to widely elliptic, 6–15 cm, herbaceous, base mostly rounded to subcordate, margins irregularly toothed or entire, apex obtuse to truncate, surfaces not papillate, sparsely hairy to glabrous, not glaucous adaxially when fresh.


Phenology: Flowering (Feb–)Mar–Jul.
Habitat: Coniferous forests, forest edges, deciduous woodlands, stream banks, coastal sage scrub, non-serpentine substrates.
Elevation: 0–2000 m.

Distribution

V12 159-distribution-map.jpg

B.C., Calif., Idaho, Mont., Oreg., Wash.

Discussion

A. R. Kruckeberg (1996) noted that a population similar to subsp. purshiana was discovered on serpentine slopes in the Wenatchee Mountains of Washington. In their shrubby habit, these plants appear to be differentiated from non-serpentine populations elsewhere in the Pacific Northwest, which are treelike in habit. The Wenatchee plants retain their shrubby habit when garden-grown from seeds.

The bark of subsp. purshiana is a valuable medicinal crop for its cathartic properties. The tree attracts an abundance of bees and other pollinators during its long flowering season, and the fruits are an important food for songbirds, pileated woodpeckers, band-tailed pigeons, and other wildlife.

Selected References

None.

Lower Taxa

None.
John O. Sawyer† +  and Guy L. Nesom +
(de Candolle) A. Gray ex J. G. Cooper +
Rhamnus purshiana +
B.C. +, Calif. +, Idaho +, Mont. +, Oreg. +  and Wash. +
0–2000 m. +
Coniferous forests, forest edges, deciduous woodlands, stream banks, coastal sage scrub, non-serpentine substrates. +
Flowering (Feb–)Mar–Jul. +
Trans. Amer. Med. Assoc. +
Rhamnus sect. Frangula +  and Rhamnus subg. Frangula +
Frangula purshiana subsp. purshiana +
Frangula purshiana +
subspecies +