Spiraea douglasii var. roseata

(Rydberg) C. L. Hitchcock

in C. L. Hitchcock et al., Vasc. Pl. Pacif. N.W. 3: 192. 1961.

Endemic
Basionym: Spiraea roseata Rydberg in N. L. Britton et al., N. Amer. Fl. 22: 250. 1908
Synonyms: S. idahoensis A. Nelson
Treatment appears in FNA Volume 9. Treatment on page 408. Mentioned on page 407.

Leaf abaxial surfaces glabrous or pubescent. Inflorescence branches glabrescent or glabrous. Pedicels glabrescent or glabrous. Flowers: hypanthia and sepals glabrescent or glabrous.


Phenology: Flowering Jun–Aug; fruiting Jul–Nov.
Habitat: Stream banks, woodland margins, meadows, roadsides
Elevation: 300–2500 m

Discussion

P. A. Rydberg (1917) considered Spiraea roseata to be a hybrid of S. densiflora and S. menziesii (here S. douglasii var. menziesii), and considered S. idahoensis to be a distinct species. At this time, it is unclear whether it is indeed a hybrid or a geographic variant of S. douglasii. The occurrence of specimens in the Columbia River region suggests a hybrid origin.

Selected References

None.

Lower Taxa

None.
Richard Lis +
(Rydberg) C. L. Hitchcock +
Spiraea roseata +
Idaho +  and Wash. +
300–2500 m +
Stream banks, woodland margins, meadows, roadsides +
Flowering Jun–Aug +  and fruiting Jul–Nov. +
in C. L. Hitchcock et al., Vasc. Pl. Pacif. N.W. +
S. idahoensis +
Spiraea douglasii var. roseata +
Spiraea douglasii +
variety +