OregonFlora: Atriplex argentea vs. Atriplex micrantha

	Atriplex argentea	Atriplex micrantha
	silverscale	twoscale saltbush
Habit		Herbs annual, monoecious, 4–17(20) dm, sparsely farinose, becoming glabrate.
Stems		erect; much branched, sometimes striate.
Leaves		mostly alternate; lowermost opposite; blades triangular-hastate to triangular-lanceolate, 1–12 cm, green on both surfaces, bases truncate to broadly cuneate; margins entire to irregularly dentate; tips acute, glabrous to sparsely scaly; petioles 20–30(40) mm.
Inflorescences		elongated spikes, sometimes arranged in panicles, staminate and pistillate flowers intermixed.
Staminate flowers		perianths 5-parted.
Pistillate flowers		dimorphic; of 2 sizes; both lacking a perianth, with 2 bracteoles.
Seeds		dimorphic, with larger bracteoles 2–2.5(3) mm, brown, with smaller bracteoles 1–1.5 mm; black to dark brown; shiny.
Fruiting bracteoles		fused just at base, broadly ovate to orbicular, 1.5–6 mm; margins entire; tips rounded; faces smooth, substipitate.
2n		=36.

	Atriplex argentea	Atriplex micrantha
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion		Streambanks, lakeshores, seasonally wet areas, ditches, sand dunes. Flowering Jul–Sep. 50–1300 m. Col, ECas, Lava, Owy. CA, ID, NV, WA; north to British Columbia, northeast to Quebec, southeast to NM; Asia, Europe. Exotic.
Source		Flora of Oregon, volume 2, page 70 Bridget Chipman
Sibling taxa	A. canescens, A. confertifolia, A. dioica, A. gardneri, A. gmelinii, A. hortensis, A. hymenelytra, A. micrantha, A. patula, A. powellii, A. prostrata, A. pusilla, A. rosea, A. truncata	A. argentea, A. canescens, A. confertifolia, A. dioica, A. gardneri, A. gmelinii, A. hortensis, A. hymenelytra, A. patula, A. powellii, A. prostrata, A. pusilla, A. rosea, A. truncata
Subordinate taxa	A. argentea var. hillmanii
Synonyms		Atriplex heterosperma
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Atriplex micrantha

silverscale

twoscale saltbush

Habit

Herbs annual, monoecious, 4–17(20) dm, sparsely farinose, becoming glabrate.

Stems

erect; much branched, sometimes striate.

Leaves

mostly alternate; lowermost opposite;

blades triangular-hastate to triangular-lanceolate, 1–12 cm, green on both surfaces, bases truncate to broadly cuneate;

margins entire to irregularly dentate;

tips acute, glabrous to sparsely scaly;

petioles 20–30(40) mm.

Inflorescences

elongated spikes, sometimes arranged in panicles, staminate and pistillate flowers intermixed.

Staminate flowers

perianths 5-parted.

Pistillate flowers

dimorphic; of 2 sizes; both lacking a perianth, with 2 bracteoles.

Seeds

dimorphic, with larger bracteoles 2–2.5(3) mm, brown, with smaller bracteoles 1–1.5 mm; black to dark brown; shiny.

Fruiting bracteoles

fused just at base, broadly ovate to orbicular, 1.5–6 mm;

margins entire;

tips rounded;

faces smooth, substipitate.

=36.

Atriplex micrantha

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Streambanks, lakeshores, seasonally wet areas, ditches, sand dunes. Flowering Jul–Sep. 50–1300 m. Col, ECas, Lava, Owy. CA, ID, NV, WA; north to British Columbia, northeast to Quebec, southeast to NM; Asia, Europe. Exotic.

Source

Flora of Oregon, volume 2, page 70
Bridget Chipman

Sibling taxa