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slender pigweed, slim amaranth

Powell's amaranth

Habit Plants mostly glabrous, villous distally when young. Plants mostly glabrous, occasionally villous near tips.
Stems

erect, branched or not, 3–12(20) dm, green or red.

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

Leaves

blades rhombic-ovate to widely lanceolate; (2)4–12(15) cm, bases wedge-shaped;

margins entire; plane;

tips acute to obtuse;

midveins extending to a spine;

petioles 1–5(10) cm.

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

terminal and axillary, tightly clustered; lax and nodding; dull green to red, villous;

bracts 2–4 mm;

midveins extending to a spine.

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 5, mostly similar in staminate and pistillate flowers; erect, not overlapping or reflexed, linear to lance-oblong;

midveins extending to spine;

tips acute.

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

generally at inflorescence tips;

perianth segments of nearly equal length, 2–3 mm;

stamens 5.

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

stamens 3–5.

Pistillate flowers

perianth segments of equal length or 1 slightly longer, 1.5–2 mm;

styles 3; erect.

perianth segments 1.5–3.5 mm;

styles 3, spreading.

Fruits

ovoid, 1.5–2.2 mm, rugose at tips; smooth below; dehiscence circumscissile.

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

Seeds

lenticular, widely orbicular to rounded, 1–1.4 mm, red-brown to black; shiny.

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

2n

=32.

=32, 34.

Amaranthus hybridus

Amaranthus powellii

Distribution
[WildflowerSearch map]
[BONAP county map]
[WildflowerSearch map]
[BONAP county map]
Discussion

Disturbed areas, streambanks, roadsides, fields. Flowering May–Oct. 0–700 m. Casc, Owy, Sisk, WV. CA, ID, NV, WA; throughout North America; scattered worldwide. Native?

Amaranthus hybridus has been known to hybridize with A. retroflexus.

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
Flora of Oregon, volume 2, page 66
Bridget Chipman
Sibling taxa
A. albus, A. blitoides, A. californicus, A. deflexus, 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