Eriogonum fusiforme

Small

Bull. Torrey Bot. Club 33: 56. 1906.

Common names: Grand Valley desert trumpet
Endemic
Synonyms: Eriogonum inflatum var. fusiforme (Small) Reveal
Treatment appears in FNA Volume 5. Treatment on page 386. Mentioned on page 383.

Herbs, spreading, annual, (0.3–) 0.5–4 dm, essentially glabrous, green or occasionally yellow-green. Stems: caudex absent; aerial flowering stems erect, usually hollow and fistulose, 0.5–1.5 dm, glabrous, villous proximally. Leaves basal; petiole 1–3 cm, hirsute; blade round, 0.5–3 × 0.5–2.5 cm, short-hirsute and greenish on both surfaces, margins plane. Inflorescences cymose, open, spreading, 5–30 × 5–30 cm; branches fistulose, glabrous; bracts 3, scalelike, 1–2 × 1–1.5 mm. Peduncles erect, straight, filiform to capillary, 1–2 cm, glabrous. Involucres turbinate, 1–1.2 × 0.7–1 mm, glabrous; teeth (4–)5, erect, 0.4–0.6 mm. Flowers 1.3–1.6 mm; perianth yellow with greenish to reddish midribs, densely hirsute with coarse curved hairs; tepals monomorphic, ovate; stamens exserted, 1.3–1.8 mm; filaments sparsely pubescent proximally. Achenes light brown, lenticular to 3-gonous, 1.3–1.8(–2) mm, glabrous.


Phenology: Flowering Apr–Jul.
Habitat: Heavy clay, sometimes gravelly flats and slopes, saltbush and greasewood communities, pinyon and/or juniper woodlands
Elevation: (900-)1100-2000 m

Discussion

Eriogonum fusiforme is widespread and common in southwestern Wyoming (Sweetwater County), eastern Utah (Carbon, Duchesne, Emery, Garfield, Grand, Kane, San Juan, Uintah, and Wayne counties), and adjacent western Colorado (Delta, Garfield, Mesa, Montrose, and Rio Blanco counties). In a “good” year, millions of individuals carpet the heavy clay flats and slopes (typically Mancos Shale), especially in Utah and Colorado. The plants can be so abundant and closely arranged that it can be difficult to walk through the tangle of stems and branches. This species is absolutely distinct from E. inflatum and no intermediates have ever been observed.

Selected References

None.

Lower Taxa

None.
... more about "Eriogonum fusiforme"
James L. Reveal +
Eriogonum sect. Ganysma +
Grand Valley desert trumpet +
Colo. +, Utah +  and Wyo. +
(900-)1100-2000 m +
Heavy clay, sometimes gravelly flats and slopes, saltbush and greasewood communities, pinyon and/or juniper woodlands +
Flowering Apr–Jul. +
Bull. Torrey Bot. Club +
Eriogonum inflatum var. fusiforme +
Eriogonum fusiforme +
Eriogonum subg. Ganysma +
species +