OregonFlora: Amaranthus muricatus vs. Amaranthus powellii

	Amaranthus muricatus	Amaranthus powellii
		Powell's amaranth
Habit		Plants mostly glabrous, occasionally villous near tips.
Stems		erect, branched or not, 2.5–15(20) dm, green or reddish purple.
Leaves		blades rhombic-ovate to broadly lanceolate, 3–6(8) cm, bases wedge-shaped; margins entire; flat to undulate; midveins extending to a short spine; tips obtuse to cuneate; petioles ? blade, 3–6 cm.
Inflorescences		mostly terminal, sometimes axillary; rigid-erect panicles with few branches, green to pale green; bracts numerous, lanceolate to awl-shaped, 4–7 mm.
Flowers		perianth segments 3–5, similar in staminate and pistillate flowers; erect, not overlapping or reflexed, broadly linear to lanceolate; midveins extending to a spine; tips acute.
Staminate flowers		perianth segments unequal to subequal, generally at tips of inflorescences; stamens 3–5.
Pistillate flowers		perianth segments 1.5–3.5 mm; styles 3, spreading.
Fruits		subglobose to ovoid, 2–3 mm; smooth to slightly rugose at tips; dehiscence circumscissile.
Seeds		subglobose to lenticular, 1–1.4 mm; black; shiny.
2n		=32, 34.

	Amaranthus muricatus	Amaranthus powellii
Distribution	[BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion		Fields, disturbed areas, roadsides, streambanks. Flowering Jun–Oct. 50–1900 m. BR, Casc, Col, CR, ECas, Lava, Owy, Sisk, WV. CA, ID, NV, WA; nearly worldwide. Native.
Source		Flora of Oregon, volume 2, page 66 Bridget Chipman
Sibling taxa	A. albus, A. blitoides, A. californicus, A. deflexus, A. hybridus, A. hypochondriacus, A. powellii, A. retroflexus, A. viridus	A. albus, A. blitoides, A. californicus, A. deflexus, A. hybridus, A. hypochondriacus, A. retroflexus, A. viridus
Web links	Local Web sites: 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

Amaranthus muricatus

Amaranthus powellii

Powell's amaranth

Habit

Plants mostly glabrous, occasionally villous near tips.

Stems

erect, branched or not, 2.5–15(20) dm, green or reddish purple.

Leaves

blades rhombic-ovate to broadly lanceolate, 3–6(8) cm, bases wedge-shaped;

margins entire; flat to undulate;

midveins extending to a short spine;

tips obtuse to cuneate;

petioles ? blade, 3–6 cm.

Inflorescences

mostly terminal, sometimes axillary; rigid-erect panicles with few branches, green to pale green;

bracts numerous, lanceolate to awl-shaped, 4–7 mm.

Flowers

perianth segments 3–5, similar in staminate and pistillate flowers; erect, not overlapping or reflexed, broadly linear to lanceolate;

midveins extending to a spine;

tips acute.

Staminate flowers

perianth segments unequal to subequal, generally at tips of inflorescences;

stamens 3–5.

Pistillate flowers

perianth segments 1.5–3.5 mm;

styles 3, spreading.

Fruits

subglobose to ovoid, 2–3 mm; smooth to slightly rugose at tips; dehiscence circumscissile.

Seeds

subglobose to lenticular, 1–1.4 mm; black; shiny.

=32, 34.

Amaranthus muricatus

Amaranthus powellii

Distribution

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Fields, disturbed areas, roadsides, streambanks. Flowering Jun–Oct. 50–1900 m. BR, Casc, Col, CR, ECas, Lava, Owy, Sisk, WV. CA, ID, NV, WA; nearly worldwide. Native.

Source

Flora of Oregon, volume 2, page 66
Bridget Chipman

Sibling taxa