Eriogonum umbellatum var. majus

Hooker

Hooker’s J. Bot. Kew Gard. Misc. 5: 264. 1853.

Common names: Subalpine sulphur flower
IllustratedEndemic
Synonyms: Eriogonum subalpinum Greene Eriogonum umbellatum subsp. majus (Hooker) Piper Eriogonum umbellatum subsp. subalpinum (Greene) S. Stokes
Treatment appears in FNA Volume 5. Treatment on page 346. Mentioned on page 335, 337, 345.

Herbs, prostrate to spreading, compact mats, 1–4.5(–5) × 2–8(–10) dm. Aerial flowering stems erect, 1.5–3 dm, usually floccose, without one or more leaflike bracts ca. midlength. Leaves in loose rosettes; blade oblanceolate to elliptic, (0.3–)0.5–2(–4) × 0.3–1(–1.5) cm, densely whitish-, greenish-, or reddish-lanate abaxially, glabrous and olive green to bright green adaxially, margins plane. Inflorescences umbellate; branches (2–)3–9 cm, usually floccose, without a whorl of bracts ca. midlength; involucral tubes 2–3.5 mm, lobes 1–4 mm. Flowers 3–7(–9.5) mm; perianth cream. 2n = 76.


Phenology: Flowering Jun–Sep.
Habitat: Sandy to gravelly flats, slopes and ridges, mixed grassland and sagebrush communities, oak, aspen, and montane to subalpine conifer woodlands, mountain meadows, or in alpine tundra
Elevation: (800-)1200-2800(-3500) m

Distribution

V5 694-distribution-map.gif

Alta., B.C., Colo., Idaho, Mont., Utah, Wash., Wyo.

Discussion

Variety majus is widespread and common in the Rocky Mountains. These plants are often locally common in Idaho and northern Utah, but they are rather rare in the Cascade Range of Washington. The high-elevation plants in Washington are often markedly different from similarly situated Rocky Mountain plants, having smaller leaves and flowers, and tighter, more compact, umbellate inflorescences.

Variety majus is distinct from and often grows with var. umbellatum in Colorado, leading many local taxonomists to distinguish the two at species rank. In Wyoming and Montana, however, var. majus occasionally is difficult to differentiate from var. dichrocephalum. Variety majus often occurs with Eriogonum heracleoides, and mixed collections occasionally are encountered. Care must be taken in the herbarium to differentiate the narrow-leaved E. heracleoides var. leucophaeum from the broader-leaved E. umbellatum var. majus, although the two do not grow together.

Selected References

None.

Lower Taxa

None.
James L. Reveal +
Hooker +
Subalpine sulphur flower +
Alta. +, B.C. +, Colo. +, Idaho +, Mont. +, Utah +, Wash. +  and Wyo. +
(800-)1200-2800(-3500) m +
Sandy to gravelly flats, slopes and ridges, mixed grassland and sagebrush communities, oak, aspen, and montane to subalpine conifer woodlands, mountain meadows, or in alpine tundra +
Flowering Jun–Sep. +
Hooker’s J. Bot. Kew Gard. Misc. +
Illustrated +  and Endemic +
Eriogonum subalpinum +, Eriogonum umbellatum subsp. majus +  and Eriogonum umbellatum subsp. subalpinum +
Eriogonum umbellatum var. majus +
Eriogonum umbellatum +
variety +