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

Photo is of parent taxon

Hillman's orach, Hillman's silverscale

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.

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.

Flowers

in axillary glomerules and terminal, interrupted spikes.

Staminate flowers

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

Seeds

brown, 1.5–2 mm wide;

radicle superior or lateral.

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.

2n

= 18, 36, 54.

= 18, 36, 54.

Atriplex argentea

Atriplex argentea var. hillmanii

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
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]
from FNA
CA; NV; OR
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.)

Key
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. 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
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
A. argentea var. argentea, A. argentea var. longitrichoma, A. argentea var. mohavensis, A. argentea var. rydbergii
Subordinate taxa
A. argentea var. argentea, A. argentea var. hillmanii, A. argentea var. longitrichoma, A. argentea var. mohavensis, A. argentea var. rydbergii
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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