Atriplex confertifolia |
Atriplex subg. Pterochiton |
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shadscale, shadscale saltbush, sheepfat, spiny saltbush |
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Habit | Shrubs, dioecious, 3–8 dm, spinescent. | Plants typically dioecious, woody, low to tall. |
Leaves | persistent, alternate; petiole 1–4 mm; blade orbiculate to ovate, elliptic, or oval, 9–25(–45) × 4–20(–25) mm, margin entire, apex obtuse. |
with Kranz anatomy, usually alternate, petiolate or sessile; blade variously shaped, margin entire, hastately lobed, or variously dentate. |
Staminate flowers | yellow, in clusters 2–4 mm wide or in spikes to 1 cm, axillary, in foliose-bracteate, divaricately branched panicles 3–15 cm. |
in axillary glomerules or more typically in naked terminal spikes or spicate panicles. |
Pistillate flowers | in similar paniculate inflorescences. |
lacking perianth. |
Seeds | 1.5–2 mm wide. |
erect; radicle superior or sublateral (in A. hymenelytra, A. lentiformis, and A. torreyi). |
Fruiting | bracteoles sessile or subsessile, suborbiculate to rhombic or elliptic, 4–12 mm and wide, body indurate, terminal teeth distinct, foliaceous, shorter than bracteoles, entire or toothed below, terminal teeth spreading at maturity, faces smooth, lacking appendages. |
bracteoles sessile or stipitate, united beyond middle to apex, variously shaped, winged or wingless, margin entire or toothed to lobed, faces tuberculate or lacking tubercles. |
2n | = 18, 36, 54+. |
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Atriplex confertifolia |
Atriplex subg. Pterochiton |
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Phenology | Flowering spring–fall. | |
Habitat | Gravelly to fine-textured soils in greasewood, mat-atriplex, other salt desert shrub, sagebrush, pinyon-juniper, and ponderosa pine communities | |
Elevation | 600-2200 m (2000-7200 ft) | |
Distribution |
AZ; CA; CO; ID; MT; ND; NM; NV; OR; TX; UT; WY
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United States; Mexico |
Discussion | Shadscale forms hybrids with Atriplex canescens, A. garrettii, A. corrugata, and A. gardneri varieties. It is, however, closely allied to A. parryi and A. spinifera. The plants are widely dispersed, typically on saline substrates but less commonly on essentially non-saline ones, through large areas of the western United States and adjacent Canada and Mexico, on both raw and exposed geological strata and on alluvium. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species 14 (14 in the flora). E. Ulbrich (1934) circumscribed section Deserticola to include all of the shrubby species of Atriplex except for Atriplex canescens, which he included within Obione subgenus Pterochiton. The name Deserticola was taken by J. McNeill et al. (1983) to include not only A. canescens per se, but representatives of other groups containing woody taxa, as treated by P. C. Standley. Atriplex canescens is known to form hybrids with numerous other taxa of woody Atriplex. Thus, most of the woody species are in some large part closely allied and capable of hybridization to a greater or lesser extent. Members of the subgenus, despite their near relationships, also show affinities that lead back through time to some ancestor or ancestors common to both them and with those of subgenus Obione. They do not, however, appear to have arisen as end points of evolution from various places within that subgenus, i.e., the subgenus Pterochiton appears to be monophyletic. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4. | FNA vol. 4. |
Parent taxa | Chenopodiaceae > Atriplex > subg. Pterochiton | Chenopodiaceae > Atriplex |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Obione confertifolia, A. collina, A. subconferta, Obione rigida | subg. Pterochiton, A. unranked Canescentes, A. unranked Confertifoliae, A. section Deserticola, A. unranked Nuttallianae, Obione section Deserticola, Obione subg. Pterochiton |
Name authority | (Torrey & Frémont) S. Watson: Proc. Amer. Acad. Arts 9: 119. (1874) | (Torrey & Frémont) S. L. Welsh: Rhodora 102: 426. (2001) |
Web links |