Eriogonum umbellatum var. cognatum

(Greene) Reveal

SouthW. Naturalist 13: 357. 1968.

Common names: Flagstaff sulphur flower
Endemic
Basionym: Eriogonum cognatum Greene Pittonia 3: 201. 1897
Synonyms: Eriogonum umbellatum subsp. cognatum (Greene) S. Stokes
Treatment appears in FNA Volume 5. Treatment on page 352. Mentioned on page 337.

Herbs, compact mats, 1–2(–2.5) × 1–3 dm. Aerial flowering stems erect, 1–1.5 dm, glabrous, without one or more leaflike bracts ca. midlength. Leaves in loose rosettes; blade oblong-obovate to elliptic or oval, (1–)1.5–2(–2.5) × 1–1.5(–2) cm, densely white-tomentose abaxially, thinly floccose or glabrous and dark green adaxially, margins plane. Inflorescences compound-umbellate, branched 2–4 times; branches glabrous, without a whorl of bracts ca. midlength; involucral tubes 3–5 mm, lobes 1–2.5 mm. Flowers 4–7 mm; perianth bright yellow.


Phenology: Flowering Jul–Sep.
Habitat: Sandy flats and slopes, sagebrush communities, oak and montane conifer woodlands
Elevation: 1600-2200 m

Discussion

Variety cognatum is localized and rather infrequent in south-central Coconino County and also barely enters Gila and Yavapai counties. It is seen most frequently in the greater Flagstaff area.

Selected References

None.

Lower Taxa

None.
James L. Reveal +
(Greene) Reveal +
Eriogonum cognatum +
Flagstaff sulphur flower +
1600-2200 m +
Sandy flats and slopes, sagebrush communities, oak and montane conifer woodlands +
Flowering Jul–Sep. +
SouthW. Naturalist +
Eriogonum umbellatum subsp. cognatum +
Eriogonum umbellatum var. cognatum +
Eriogonum umbellatum +
variety +