Eriogonum microtheca var. ambiguum

(M. E. Jones) Reveal

in P. A. Munz, Suppl. Calif. Fl., 61. 1968.

Common names: Yellow-flowered wild buckwheat
Endemic
Basionym: Eriogonum aureum var. ambiguum M. E. Jones Proc. Calif. Acad. Sci., ser. 2, 5: 719. 1895
Treatment appears in FNA Volume 5. Treatment on page 247. Mentioned on page 243.
Revision as of 20:12, 27 October 2022 by GeoffLevin (talk | contribs) (Fixed italics in discussion)

Subshrubs or shrubs, 0.5–5 × 1–8 dm. Stems: caudex absent; aerial flowering stems 0.2–1 dm, mostly floccose. Leaves: blade 0.8–2.5 × (0.2–)0.3–0.6(–0.8) cm, densely white- or reddish-brown-tomentose abaxially, floccose adaxially, margins rarely revolute. Inflorescences 1–5(–12) cm; branches tomentose to floccose. Involucres 2–2.5 mm, tomentose to floccose. Flowers (1.5–)2–2.5(–3) mm; perianth yellow. Achenes 1.5–2 mm.


Phenology: Flowering Jul–Sep.
Habitat: Sandy to rocky soil, sagebrush and saltbush communities, pinyon-juniper and conifer woodlands
Elevation: (1100-)1900-3300 m

Distribution

V5 458-distribution-map.gif

Calif., Idaho, Nev., Oreg.

Discussion

Variety ambiguum,/i> occurs in eastern California, northwestern Nevada, and southeastern Oregon. In portions of its range, var. ambiguum appears to be little more than a yellow-flowered phase of var. laxiflorum. However, where the two occur together, intermediates are rarely found, and limited garden studies indicate that flower color is genetically fixed. Nonflowering specimens from southern Owyhee County, Idaho, have been tentatively assigned to this taxon.

Selected References

None.

Lower Taxa

None.
James L. Reveal +
(M. E. Jones) Reveal +
Eriogonum aureum var. ambiguum +
Yellow-flowered wild buckwheat +
Calif. +, Idaho +, Nev. +  and Oreg. +
(1100-)1900-3300 m +
Sandy to rocky soil, sagebrush and saltbush communities, pinyon-juniper and conifer woodlands +
Flowering Jul–Sep. +
in P. A. Munz, Suppl. Calif. Fl., +
Eriogonum microtheca var. ambiguum +
Eriogonum microtheca +
variety +