Atriplex argentea |
Atriplex argentea var. hillmanii |
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maidenhair spleenwort, silver orach, silver orache, silver saltbush, silverscale, silverscale orache, silverscale saltbush, silvery orache |
Hillman's orach, Hillman's silverscale |
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Habit | Herbs, simple or freely branched, 0.5–6 dm; branches rather stout, angled, scurfy when young. | |||||||||||||||||
Stems | spreading or ascending, densely branched, forming low broad clumps, 1.5–3(–4.5) dm. |
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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). |
blade ovate-oval, triangular, or oval to broadly oblong or rhombic-orbicular, 8–30 mm, base acute to subtruncate, margin entire or less commonly irregularly dentate, grayish scurfy. |
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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. |
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Seeds | brown, 1.5–2 mm wide; radicle superior or lateral. |
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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 rarely some short stipitate (stipe to 2 mm), ovate to obovate, suborbicular, or cuneate in profile, compressed or thickened, 3.5–6.2 × 3.7–7.2 mm, margin deeply and acutely dentate, faces naked or covered with numerous short to elongate, flattened appendages. |
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2n | = 18, 36, 54. |
= 18, 36, 54. |
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Atriplex argentea |
Atriplex argentea var. hillmanii |
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Phenology | Flowering summer–fall. | |||||||||||||||||
Habitat | Dry or moist saline, silt or clay substrates mainly in valley bottoms | |||||||||||||||||
Elevation | 1000-1800 m (3300-5900 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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CA; NV; OR |
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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.) |
Atriplex argentea var. hillmanii often occurs with Sarcobatus, Atriplex spp., Halogeton, Salsola, and Chrysothamnus. The features used to distinguish this taxon from var. argentea center on the mostly sessile fruiting bracteoles, which typically bear acute-attenuate or acuminate processes, and on the tendency of the plants to grow in depressed low clumps mainly less than 3 dm tall. These features are not always consistent, and neither are they consistently associated. Some plants bear occasional short stipitate fruiting bracteoles, and in some the appendages are merely acute. Examples of much taller plants are also known. Despite the lack of totally consistent characteristics, the entity has a geographic basis, with western Nevada at its approximate center and minor extensions into adjacent southeastern California and southeastern Oregon. (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, p. 351. | ||||||||||||||||
Parent taxa | Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Argenteae | Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Argenteae > Atriplex argentea | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | Obione argentea | A. hillmanii | ||||||||||||||||
Name authority | Nuttall: Gen. N. Amer. Pl. 1: 198. (1818) | M. E. Jones: Contr. W. Bot. 11: 21. (1903) | ||||||||||||||||
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