Allenrolfea occidentalis (S. Wats.) Kuntze

Common names: Iodine bush, pickle-weed.
Family: Chenopodiaceae
Synonymy: Halostachys occidentalis (S. Wats.).
Etymology: The genus refers to Robert Allen Rolfe an English Botanist (1855-1921) (6). The common name is derived from the color of the dried sap of crushed leaves (2).   

Identification
Growth form: Iodine bush is a shrub that reaches 30cm to 1m in height (4,5).
Roots: Iodine bush has a large shallow root system that has been found to extend as far out as 10 meters. The roots obtain most of their water from surface water that sinks into the mounds that the plants grow on (7).
Stem: Stems are succulent, although woody below, erect or decumbent, alternate with branches that are articulated into small joints (3,6)
Leaves: Leaves are reduced to scales (6).
Inflorescence/flowers: Numerous inflorescence with the flowers being non-showy and in terminal spikes (6).
Fruit: Utricle ovoid, enclosed by the calyx. Seeds are brown to reddish brown, dispersed by wind or water and can germinate in up to 700mM NaCl (4,6).
Similar species: This is the only species within the genus Allenrolfea (5).

Ecology
Life history: Perennial
Native/introduced: Native to salt deserts of the Western United States and Northwest Mexico (4).
Photosynthetic pathway: C 3 (3)
Phenology: The growing season for iodine bush spans 7 months (May-Nov). Flowering occurs during late summer and seeds mature in the early fall (1).
Distribution: Restricted to salt playas where the soils are poorly drained and have high salinity. Found in Arizona (5,000ft or lower), California, Idaho, New Mexico, Nevada, Oregon, Texas, Utah and Mexico (3,6).

Uses
Provides little forage for livestock (2). No other known uses.

References

  1. Blank, R.R., Young, J.A, Martens, E. and D.E. Palmquist. 1994. Influence of temperature and osmotic potential on germination of Allenrolfea occidentalis seeds.
  2. Benson, L. and A. Darrow. 1945. Southwestern desert trees and shrubs. University of Arizona, Tucson, Arizona.
  3. Gul, B., Weber, D.J., M. Ajmal Khan. 2000. Growth, ionic and osmotic relations of an Allenrolfea occidentalis population in an inland salt playa of the Great Basin Desert. Journal of Arid Environments. 48:445-460.
  4. Gul, B., and D.J. Weber. 1998. Effect of dormancy relieving compounds on seed germination of non-dormant Allenrolfea occidentalis under salinity stress. Annals of Botany. 82:555-560.
  5. USDA Natural Resource Conservation Service Plants Profile. http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=ALOC2#distribution
  6. Shultz, L.M. http://www.fna.org/FNA/allenrolfea.html.
  7. Trent, I.D., R.R. Blank, J.A. Young. 1997. Ecophysiology of the temperate desert halophytes: Allenrolfea occidentalis and Sarcobatus vermiculatus . Great Basin Naturalist 57:57-65.