Amaranthus wrightii

S. Watson

Proc. Amer. Acad. Arts 12: 275. 1877.

Common names: Wright’s amaranth
Endemic
Treatment appears in FNA Volume 4. Treatment on page 422. Mentioned on page 415.

Plants glabrous or nearly so. Stems erect or ascending, often whitish or tinged with red, simple to sparingly branched distally, or occasionally basally, 0.2–1 m. Leaves: petiole shorter than to ± equaling blade; blade rhombic-ovate to elliptic-lanceolate, 1.5–6 × 0.5–3 cm, base broadly to narrowly cuneate, margins entire, plane to slightly undulate, apex obtuse to subacute, or shallowly emarginate, with terminal mucro. Inflorescences terminal and axillary in distal part of plant, erect, usually reddish green, branched, leafless at least distally, short and thick. Bracts linear-lanceolate to subulate, to 2 times as long as tepals, apex spinescent. Pistillate flowers: tepals 5, spatulate-linear, not clawed, subequal or unequal, 1.5–2 mm, membranaceous, apex emarginate or retuse to obtuse, outer tepals with apex rarely subacute; style-branches shorter than body of fruit; stigmas 3. Staminate flowers few at tips of inflorescences; tepals 5; stamens 4–5. Utricles subglobose to broadly obovoid, 1.3–2 mm, equal or subequal to tepals, smooth or slightly rugose, dehiscence regularly circumscissile. Seeds dark reddish-brown to nearly black, lenticular to subglobose-lenticular, 1 mm diam., smooth, shiny.


Phenology: Flowering summer–fall.
Habitat: Naturally disturbed habitats, streambanks, canyons, semideserts
Elevation: 500-2000 m

Distribution

Ariz., Colo., N.Mex., Tex.

Discussion

Amaranthus wrightii seems to be closely related to A. retroflexus. In some herbaria the specimens of A. acanthochiton J. D. Sauer (previously known as Acanthochiton wrightii Torrey, see above) were mechanically “transferred” to Amaranthus and erroneously placed in folders as “Amaranthus wrightii.” That confusion was caused by the identical species epithets; these two taxa are dramatically different morphologically. Amaranthus wrightii may also occur in adjacent Mexico.

Selected References

None.

Lower Taxa

None.

"-2timesaslongastepals" is not declared as a valid unit of measurement for this property."thick" is not a number.

... more about "Amaranthus wrightii"
subacute;retuse;obtuse +
Sergei L. Mosyakin +  and Kenneth R. Robertson +
S. Watson +
cuneate +
1.5 cm15 mm <br />0.015 m <br /> (6 cm60 mm <br />0.06 m <br />) +
rhombic-ovate +  and elliptic-lanceolate +
0.5 cm5 mm <br />0.005 m <br /> (3 cm30 mm <br />0.03 m <br />) +
persistent +
linear-lanceolate +  and subulate +
Wright’s amaranth +
Ariz. +, Colo. +, N.Mex. +  and Tex. +
500-2000 m +
peripheral +
staminate +  and pistillate +
hypogynous +
minute +  and small +
not +  and dehiscent +
Naturally disturbed habitats, streambanks, canyons, semideserts +
leafless +  and branched +
reduced +
plane +  and slightly undulate +
scarious +  and membranaceous +
cylindric +
Flowering summer–fall. +
rudimentary +
Proc. Amer. Acad. Arts +
dark reddish-brown +  and nearly black +
lenticular +  and subglobose-lenticular +
cylindric +
simple +  and sparingly branched +
tinged with red +  and whitish +
prostrate +  and decumbent +
ascending +  and erect +
20 cm200 mm <br />0.2 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not fleshy +
slender +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
Acanthochiton +, Acnida +, Albersia +, Amblogyna +, Euxolus +, Mengea +, Sarratia +  and Scleropus +
Amaranthus wrightii +
Amaranthus subg. Amaranthus +
species +
distinct +
not clawed +
unequal +  and subequal +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranaceous +
walled +  and 3(-5)-veined +
circumscissile +
rugose +  and smooth +
subglobose +  and broadly obovoid +
subequal +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranaceous +
nearly +  and glabrous +