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Powell's orach, Powell's orache, Powell's saltbush, Powell's saltweed

maidenhair spleenwort, silver orach, silver orache, silver saltbush, silverscale, silverscale orache, silverscale saltbush, silvery orache

Habit Herbs, dioecious or sometimes sparingly monoecious. Herbs, simple or freely branched, 0.5–6 dm; branches rather stout, angled, scurfy when young.
Stems

slender to stout, mainly 1–5(–7) dm, branching almost throughout;

herbage pubescent with scurfy and arachnoid hairs.

Leaves

alternate, proximalmost on petioles (3–)5–30 mm, becoming subsessile or short petiolate distally;

blade 3-veined, ovate to rhombic or orbiculate to elliptic, 0.4–5 × 0.2–3 cm, base rounded to cuneate, margin entire, apex acute to obtuse.

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).

Flowers

in axillary glomerules and terminal, interrupted spikes.

Staminate flowers

with calyx 4–5-lobed.

borne in distal axils, or in short dense spikes or panicles, or intermixed with pistillate, with 4–5-parted calyx.

Seeds

greenish, yellowish, or brown, 0.9–2 mm;

radicle superior.

brown, 1.5–2 mm wide;

radicle superior or lateral.

Fruiting

bracteoles sessile, ovate to oblong or broadly cuneate or pan-duriform, 1.5–5.5 × 1.5–5 mm, thick, united to apex, apex truncate to cuspidate or tridentate, surfaces with thickened processes or rarely smooth.

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.

2n

= 18.

= 18, 36, 54.

Atriplex powellii

Atriplex argentea

Distribution
from FNA
AZ; CO; ID; MT; NE; NM; OR; SD; UT; WY; AB; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; CO; ID; KS; MT; ND; NE; NM; NV; OK; OR; SD; TX; UT; WA; WY; AB; BC; MB; SK; Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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.)

Key
1. Leaves mostly conspicuously 3-veined, proximalmost with petioles 0.5-2.5(-3.5) cm, distalmost bracteate leaves typically short petiolate; fruiting bracteoles easily discerned at bract bases; plants mostly dioecious; from Alberta and Saskatchewan s to Utah and New Mexico
var. powellii
1. Leaves inconspicuously, if at all, 3-veined, proximalmost with petioles 0.5-1.5(-2) cm, distalmost bracteate leaves typically sessile; fruiting bracteoles apparent only by removing the subtending bract; plants evidently monoecious; local distribution in se Utah.
var. minuticarpa
1. Plants low, rounded, mainly 1-3(-4.5) dm; fruiting bracteoles sessile or rarely some short stipitate, the appendages mainly acuminate or acute-attenuate; Nevada and adjacent se California, se Oregon
→ 2
1. Plants rather strict and often taller, mainly 2-4(-5) dm; fruiting bracteoles, at least some, short stipitate; appendages acute to less commonly acuminate to attenuate; other distribution
→ 3
2. Leaf blades typically, but not always, constricted to the petiole; herbage merely scurfy, or with elongate trichomes mainly on the fruiting bracteoles; Nevada (except the southern part), and adjacent se California and se Oregon
var. hillmanii
2. Leaf blades typically, if not always, cuneate to a winged petiole or merely sessile base; herbage copiously covered with elongate trichomes throughout, or mostly on the stems and fruiting bracteoles; Nye County, Nevada and adjacent Inyo County, California
var. longitrichoma
3. Leaf blades elliptic to oval, attenuate to a cuneate base; sw Colorado, se Utah, and nw New Mexico
var. rydbergii
3. Leaf blades triangular-ovate to oval, base broadly obtuse to acute or less commonly cuneate; various or other distribution
→ 4
4. Distal leaves short petiolate; proximalmost leaves alternate; plants mostly less than 4 dm; British Columbia to Manitoba, s through Montana, North Dakota, South Dakota, Wyoming, Nebraska, Idaho, Utah, e Nevada, Colorado, w Kansas, ne Arizona, nw New Mexico
var. argentea
4. Distal leaves sessile; proximalmost leaves opposite; plants mostly over 4 dm; California, s Nevada, Arizona, New Mexico, w Oklahoma, w and n Texas
var. mohavensis
Source FNA vol. 4, p. 352. FNA vol. 4.
Parent taxa Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Argenteae Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Argenteae
Sibling taxa
A. acanthocarpa, A. amnicola, A. argentea, A. californica, A. canescens, A. confertifolia, A. cordulata, A. coronata, A. corrugata, A. coulteri, A. covillei, A. dioica, A. elegans, A. fruticulosa, A. gardneri, A. garrettii, A. glabriuscula, A. gmelinii, A. graciliflora, A. heterosperma, A. holocarpa, A. hortensis, A. hymenelytra, A. joaquiniana, A. klebergorum, A. laciniata, A. lentiformis, A. leucophylla, A. lindleyi, A. linearis, A. littoralis, A. matamorensis, A. mucronata, A. nudicaulis, A. nummularia, A. oblongifolia, A. obovata, A. pacifica, A. parishii, A. parryi, A. patula, A. pentandra, A. phyllostegia, A. pleiantha, A. polycarpa, A. prostrata, A. pusilla, A. rosea, A. saccaria, A. semibaccata, A. serenana, A. spinifera, A. suberecta, A. suckleyi, A. tatarica, A. torreyi, A. truncata, A. tularensis, A. watsonii, A. wolfii, A. wrightii
A. acanthocarpa, A. amnicola, A. californica, A. canescens, A. confertifolia, A. cordulata, A. coronata, A. corrugata, A. coulteri, A. covillei, A. dioica, A. elegans, A. fruticulosa, A. gardneri, A. garrettii, A. glabriuscula, A. gmelinii, A. graciliflora, A. heterosperma, A. holocarpa, A. hortensis, A. hymenelytra, A. joaquiniana, A. klebergorum, A. laciniata, A. lentiformis, A. leucophylla, A. lindleyi, A. linearis, A. littoralis, A. matamorensis, A. mucronata, A. nudicaulis, A. nummularia, A. oblongifolia, A. obovata, A. pacifica, A. parishii, A. parryi, A. patula, A. pentandra, A. phyllostegia, A. pleiantha, A. polycarpa, A. powellii, A. prostrata, A. pusilla, A. rosea, A. saccaria, A. semibaccata, A. serenana, A. spinifera, A. suberecta, A. suckleyi, A. tatarica, A. torreyi, A. truncata, A. tularensis, A. watsonii, A. wolfii, A. wrightii
Subordinate taxa
A. powellii var. minuticarpa, A. powellii var. powellii
A. argentea var. argentea, A. argentea var. hillmanii, A. argentea var. longitrichoma, A. argentea var. mohavensis, A. argentea var. rydbergii
Synonyms Obione powellii Obione argentea
Name authority S. Watson: Proc. Amer. Acad. Arts 9: 114. (1874) Nuttall: Gen. N. Amer. Pl. 1: 198. (1818)
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