Eriogonum marifolium

Torrey & A. Gray

Proc. Amer. Acad. Arts 8: 161. 1870.

Common names: Marum-leaf wild buckwheat
IllustratedEndemic
Synonyms: Eriogonum cupulatum S. Stokes Eriogonum marifolium var. apertum S. Stokes
Treatment appears in FNA Volume 5. Treatment on page 365. Mentioned on page 334.

Herbs, matted, dioecious, (0.1–)0.5–5 × 2–8 dm, floccose or glabrous. Stems: caudex spreading; aerial flowering stems erect, slender, solid, not fistulose, arising at nodes of caudex branches and at distal nodes of short, non-flowering aerial branches, (0.1–)0.5–4 dm, floccose or glabrous. Leaves in loose to compact basal rosettes; petiole 0.3–2 cm, often tomentose; blade ovate to oval, 0.3–3 × 0.3–1 cm, densely tannish- to brownish-lanate abaxially, glabrate and green to olive green adaxially, margins entire, plane. Inflorescences capitate, 0.5–2 cm wide, mature pistillate plants open and elongate-umbellate, 1–5 × 1–7 cm; branches usually glabrous; bracts 5–10, leaflike, 0.2–0.8 cm, often absent immediately below involucre. Involucres 1 per node but occasionally appearing congested, turbinate and 2–3 × 1.5–2 mm or campanulate and 4–5 × 5–7 mm, sparsely tomentose or glabrous; teeth 5–6, erect, 0.4–0.7 mm. Flowers stipelike base 0.5–1 mm; perianth yellow, glabrous; staminate flowers 1.5–3 mm, tepals ovate; pistillate flowers 4–7 mm, tepals oblanceolate, often becoming reddish in fruit; stamens exserted, 2–3 mm; filaments pilose proximally. Achenes light brown to brown, 3.5–5 mm, glabrous except for sparsely pubescent beak. 2n = 32.

Discussion

Varieties 2 (2 in the flora).

Eriogonum marifolium is dioecious, with the two sexes having such markedly different morphology that collectors often consider each to represent a different species. In Oregon, male plants of E. marifolium and E. umbellatum var. haussknechtii can be difficult to distinguish. In El Dorado and Placer counties, California, herbarium specimens of E. marifolium and E. incanum can be difficult to separate, as their distribution ranges overlap there.

Selected References

None.

Key

1 Involucres turbinate, 2-3 × 1.5-2 mm; ne California, wc Nevada, s Oregon, disjunct to Yakima County, Washington Eriogonum marifolium var. marifolium
1 Involucres campanulate, 4-5 × 5-7 mm; nc California Eriogonum marifolium var. cupulatum