Atriplex argentea |
Atriplex confertifolia |
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maidenhair spleenwort, silver orach, silver orache, silver saltbush, silverscale, silverscale orache, silverscale saltbush, silvery orache |
shadscale, shadscale saltbush, sheepfat, spiny saltbush |
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Habit | Herbs, simple or freely branched, 0.5–6 dm; branches rather stout, angled, scurfy when young. | Shrubs, dioecious, 3–8 dm, spinescent. | ||||||||||||||||
Leaves | often opposite proximally, petiolate or distal bracteate ones subsessile, blade lance-ovate, lanceolate, deltoid, or cordate, 5–75 × 4–50(–75) mm, base subhastate or obtuse to acute, margin entire or essentially so, sometimes closely repand-dentate, apex obtuse to acute or rounded, scurfy (glabrous). |
persistent, alternate; petiole 1–4 mm; blade orbiculate to ovate, elliptic, or oval, 9–25(–45) × 4–20(–25) mm, margin entire, apex obtuse. |
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Flowers | in axillary glomerules and terminal, interrupted spikes. |
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Staminate flowers | borne in distal axils, or in short dense spikes or panicles, or intermixed with pistillate, with 4–5-parted calyx. |
yellow, in clusters 2–4 mm wide or in spikes to 1 cm, axillary, in foliose-bracteate, divaricately branched panicles 3–15 cm. |
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Pistillate flowers | in similar paniculate inflorescences. |
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Seeds | brown, 1.5–2 mm wide; radicle superior or lateral. |
1.5–2 mm wide. |
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Fruiting | bracteoles sessile, subsessile, or stipitate (stipe 0.5–5 mm), cuneate-orbicular, (2.5–)4–11.2 × 2–8.8(–14) mm, margin foliaceous below apex, subentire or dentate to laciniate, face smooth, tuberculate, or crested, processes sometimes again toothed, teeth then aligned with axis of process. |
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. |
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2n | = 18, 36, 54. |
= 18, 36, 54+. |
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Atriplex argentea |
Atriplex confertifolia |
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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; KS; MT; ND; NE; NM; NV; OK; OR; SD; TX; UT; WA; WY; AB; BC; MB; SK; Mexico
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AZ; CA; CO; ID; MT; ND; NM; NV; OR; TX; UT; WY
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Discussion | Varieties 5 (5 in the flora). Herbarium materials have tended to represent a catchall for annual specimens not readily assignable to other taxa. Indeed, the distinguishing features of the Atriplex argentea complex are shared singly and often in combination with other taxa. Only by use of combinations of features can this taxon be defined. Those features, with much variation, center around the broad, typically ovate to deltoid leaf blades (often definitely 3-veined) and more-or-less compressed, sessile to subsessile (or short stipitate), fruiting bracteoles on which the marginal processes, or teeth, are mainly aligned with the plane compression, and with the faces quite smooth to variously appendaged. Still some specimens are apparently intermediate with other species, especially with the closely allied A. saccaria, with which it is at least partially sympatric. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
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Key |
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Source | FNA vol. 4. | FNA vol. 4. | ||||||||||||||||
Parent taxa | Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Argenteae | Chenopodiaceae > Atriplex > subg. Pterochiton | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | Obione argentea | Obione confertifolia, A. collina, A. subconferta, Obione rigida | ||||||||||||||||
Name authority | Nuttall: Gen. N. Amer. Pl. 1: 198. (1818) | (Torrey & Frémont) S. Watson: Proc. Amer. Acad. Arts 9: 119. (1874) | ||||||||||||||||
Web links |
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