Isocoma acradenia is a North American species of flowering plant in the family Asteraceae known by the common name alkali goldenbush.

Isocoma acradenia
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Genus: Isocoma
Species:
I. acradenia
Binomial name
Isocoma acradenia
(Greene) Greene 1894
Synonyms[1]
Synonymy
  • Bigelowia acradenia Greene 1883
  • Bigelovia acradenia Greene 1883
  • Haplopappus acradenia (Greene) S.F.Blake
  • Isocoma veneta var. acradenia (Greene) H.M. Hall
  • Aster acradenius (Greene) Kuntze
  • Haplopappus acradenius (Greene) S.F.Blake
  • Isocoma limitanea Rose & Standl.
  • Isocoma veneta var. acradenia (Greene) H.M.Hall
  • Isocoma eremophila Greene
  • Isocoma bracteosa Greene

It is native to the Southwestern United States (California, Nevada, Utah, Arizona) and northwestern Mexico (Sonora, Baja California). It grows in arid, sandy areas, particularly mineral-rich areas such as alkali flats and gypsum soils.[2][3][4][5][6]

Description

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Isocoma acradenia is a bushy subshrub reaching maximum heights of slightly over 1 m (39 in). It produces erect, branching stems which are a shiny pale yellowish white, aging to a yellow-gray.[7]

Along the tough, hard-surfaced stems are linear or oval-shaped glandular leaves 1–6 cm (0.39–2.36 in) long, sometimes with stumpy teeth along the edges. They are gray-green and age to pale gray or tan.[7]

The inflorescences along the top parts of the stem branches are clusters of four or five flower heads.[8] Each head is a capsule encased in bumpy, glandular greenish phyllaries bearing many golden yellow disc florets at its mouth. Each disc floret is somewhat cylindrical and protruding.[7]

The fruit is an achene a few millimeters long, with a yellowish pappus adding another few millimeters.[7]

Varieties[7][5][4][1]
  • Isocoma acradenia var. acradenia - Salt scrub, often with creosote - Arizona, California, Nevada, Sonora
  • Isocoma acradenia var. bracteosa (Greene) G. L. Nesom - salt flats - southern Central Valley in California
  • Isocoma acradenia var. eremophila (Greene) G. L. Nesom - sandy soils, dunes, etc. - Arizona, California, Nevada, Utah, Baja California, Sonora).

References

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  1. ^ a b The Plant List, Isocoma acradenia (Greene) Greene
  2. ^ C.Michael Hogan, ed. 2010. Isocoma acradenia. Encyclopedia of Life
  3. ^ Biota of North America Program 2014 county distribution map
  4. ^ a b Calflora taxon report, University of California, Isocoma acradenia (E. Greene) E. Greene, Desert isocoma, alkali goldenbush
  5. ^ a b SEINet, Southwestern Biodiversity, Arizona chapter
  6. ^ Nesom, G.L. 1991. Taxonomy of Isocoma (Compositae: Astereae). Phytologia 70(2): 69–114 includes distribution map on page 72
  7. ^ a b c d e Flora of North America Editorial Committee (ed.). "Isocoma acradenia". Flora of North America North of Mexico (FNA). New York and Oxford: Oxford University Press – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  8. ^ Jepson Manual Treatment, University of California, (TJM93) of Isocoma acradenia
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