Amaranthaceae

Intermountain Flora, v. 2A, p. 547

• 1. Leaves alternate; flowers inisexual or bisexual.
• 2. Flowers bisexual; sepals 5.5-9 mm long; fruit a 3-8-seeded capsule, 3-4 mm long; plants cultivated. Celosia argentea

Celosia argentea

• 2' Flowers inisexual (rarely bisexual in some A. californicus); sepals of each sex less than 5 mm long; fruit a 1-seeded capsule or utricle, less than 3 mm long; plants weedy and widesprwad. Amaranthus
• 1' Leaves opposite, at least the upper ones; flowers bisexual.
• 3. Inflorescence of axillary spicate glomerules; leaves 0.5-3 cm long; sepals distinct, pilose.
• 4. Herbage woolly pubescent with branched hairs; sepals 1.2-2.3 mm long; bracts leaf-like but sessile; native. Tidestromia
• 4.1. Perennial subshrubs; pubescence a dense whitish to pale gray mat of short, branched hairs throughout; sepals 1.2-2-(2.2) mm long; Washington, Kane counties. Tidestromia oblongifolia

Tidestromia oblongifolia	Tidestromia oblongifolia	Tidestromia oblongifolia[SH]

• 4.1' Annuals; pubescence somewhat sparser, of coarser branched hairs, the leaves grayish green; sepals 2-2.3 mm long; Washington, Kane, San Juan counties. Tidestromia lanuginosa

Tidestromia lanuginosa	Tidestromia lanuginosa[SH]	Tidestromia lanuginosa	Tidestromia lanuginosa[SH]

• 4' Herbage sparsely pilose with simple hairs or glabrous; sepals 3-5 mm long, 3 large and 2 small; bracts sepal-like, scarious; introduced; not in Utah. Alternanthera caracasana

Alternanthera caracasana	Alternanthera caracasana

• 3' Inflorescence of mostly terminal spicate glomerules on an elongate, interrupted rachis; leaves 3-10 cm long; sepals inited most of their length, the tube becoming urn-shaped, sometimes with 1-3 blunt teeth, these details obscured by thick, woolly pubescence; not in Utah. Froelichia gracilis

Froelichia gracilis	Froelichia gracilis	Froelichia gracilis

Intermountain Flora, v. 2A, p. 549

• 1. Stems commonly erect or ascending; glomerules (clusters of flowers) in well-developed terminal spikes or panicles and in leaf axils (A. albus lacking a terminal spike); bracts of various sizes; fruits mostly with circumscissile dehiscence (capsules).
• 2. Plants mostly with pistillate flowers and fewer staminate flowers (monoecious), sometimes only pistillate flowers (dioecious).
• 3. Leaves (ob)lanceolate to (ob)ovate or oblong; pistillate sepals not expanded distally (except in A. palmeri and A. torreyi).
• 4. Leaf margin crisped to undulate; widespread species.
• 5. Inflorescences terminal and axillary, the terminal ones well developed; principal leaves 2-11 cm long; stems villous; bracts 3-7 mm long; fruit 1.5-2.2 mm long; pistillate sepals 5, 1.6-3.2 mm long; anthers 0.9-1.2 mm long.
• 6. Apex of the pistillate sepals obtuse to rounded and often emarginate. Amaranthus retroflexus

Amaranthus retroflexus	Amaranthus retroflexus	Amaranthus retroflexus	Amaranthus retroflexus

• 6' Apex of the pistillate sepals acute to acuminate, spinose-tipped; Piute, Iron, Washington, Garfield, San Juan counties. Amaranthus powellii

Amaranthus powellii	Amaranthus powellii	Amaranthus powellii	Amaranthus powellii

• 5' Inflorescences of axillary spicate clusters only; principal leaves 1-2.5-(3.2) cm long; stems papillate-puberulent; bracts 2-3-(3.5) mm long; fruit 1.1-1.4-(1.7) mm long; pistillate sepals 3, 0.8-1.5 mm long; anthers about 0.6 mm long. Amaranthus albus

Amaranthus albus	Amaranthus albus

• 4' Leaf margin entire, plane.
• 7. Fruit (1.5)-1.7-2.5 mm long.
• 8. Principal leaves 1-4-(5) cm wide; seeds always dark reddish brown to black; inflorescences dull greenish or sometimes pale reddish, not showy; throughout our area as weeds.
• 9. Bracts 4.2-7 mm long; terminal inflorescences stiffly erect; pistillate sepals 1.6-3.2 mm long; Piute, Iron, Washington, Garfield, San Juan counties. Amaranthus powellii

Amaranthus powellii	Amaranthus powellii	Amaranthus powellii	Amaranthus powellii

• 9' Bracts 2-4.2 mm long; terminal inflorescences often nodding pistillate sepals 1.4-2-(2.5) mm long. Amaranthus hybridus

Amaranthus hybridus	Amaranthus hybridus	Amaranthus hybridus

• 8' Principal leaves 3.2-14 cm wide; seeds dull cream, ivory or dark reddish brown; inflorescences usually very large and showy, red, purple or sometimes yellowish; cultivated ornamentals, sometimes escaping but not known to persist in our area.
• 10. Bracts 0.9-2.5 mm long, the pistillate sepals with rounded to obtuse apices; anthers 0.5-0.6 mm long; cultivated plant. Amaranthus cruentus

Amaranthus cruentus	Amaranthus cruentus	Amaranthus cruentus

• 10' Bracts 2.6-4 mm long, the pistillate sepals with acute to acuminate apices; anthers 0.8-1 mm long. Amaranthus hypochondriacus

Amaranthus hypochondriacus	Amaranthus hypochondriacus

• 7' Fruit 1-1.5-(1.6) mm long.
• 11. Bracts small and inconspicuous, 1-1.6 mm long; pistillate sepals none or occasionally 1 or 2, these rudimentary or no more than 1.5 mm long; fruits mostly indehiscent (utricles), sometimes with irregular or circumscissile dehiscence (capsules); seeds 0.7-0.9 mm long; in our area in SW Idaho and SW Utah: Washington county. Amaranthus tuberculatus

Amaranthus tuberculatus	Amaranthus tuberculatus	Amaranthus tuberculatus

• 11' Bracts 2.2-6.5 mm long; pistillate sepals 5, 1.5-3.5 mm long; fruits always with circumscissile dehiscence; seeds 0.9-1.2 mm long.
• 12. Sepals of pistillate flowers equal or subequal; plants monoecious but staminate flowers sparse; bracts of both sexes 2.2-4 mm long; anthers 0.5-0.9 mm long; in our area in N Arizona (Coconino, Mojave counties). Amaranthus torreyi

Amaranthus torreyi	Amaranthus torreyi	Amaranthus torreyi

• 12' Sepals of pistillate flowers unequal, 2 large and 3 small; plants dioecious; bracts dimorphic, the staminate bracts 2.7-4-(6) mm long and pistillate bracts 3-6.5 mm long; anthers 1-1.4 mm long; in W U.S. from California, S Nevada, SW Utah and Colorado, southward; Washington, San Juan counties. Amaranthus palmeri

Amaranthus palmeri	Amaranthus palmeri

• 3' Leaves linear to narrowly lanceolate; pistillate sepals all or at least some in the same flower expanded distally (fan-shaped).
• 13. Bracts of both sexes similar, ovate to lanceolate, 1-4 mm long; plants monoecious; staminate sepals 1.3-1.8 mm long; pistillate sepals 1.5-3 mm long; anthers 0.5-0.9 mm long.
• 14. Leaves narrowly lanceolate to ovate, 4-20 mm wide; bracts 2.2-4 mm long, as long as or longer than the sepals; pistillate sepals 1.5-2.2-(2.5) mm long, 0.5-1.6 mm wide, the apex entire to crenulate; in our area in N Arizona (Coconino, Mohave counties). Amaranthus torreyi

Amaranthus torreyi	Amaranthus torreyi	Amaranthus torreyi

• 14' Leaves linear, 1-4.5 mm wide; bracts small, 1-2.1 mm long, shorter than the sepals; pistillate sepals 2-3 mm long, 1-2.5 mm wide, the apex fimbriate to denticulate; S California, S Nevada and SW Utah, sounthward; Washington county. Amaranthus fimbriatus

Amaranthus fimbriatus	Amaranthus fimbriatus	Amaranthus fimbriatus[SH]	Amaranthus fimbriatus

• 13' Bracts dimorphic, the staminate bracts 2-3 mm long and the pistillate bracts becoming much enlarged in fruit to 5-9 mm long, broadly rhombic-ovate to deltate-reniform with a truncate to cordate base and a rigid, spinose apex; plants dioecious; staminate sepals 2.3-4 mm long; pistillate sepals (the longer pair) 2.5-1.7 mm long; anthers 0.5-0.9 mm long; S Utah, southward: Kane county. Amaranthus acanthochiton

Amaranthus acanthochiton	Amaranthus acanthochiton

• 2' Plants with staminate flowers only (dioecious); Washington, Kane, San Juan counties.
• 15. Leaves (ob)lanceolate to (ob)ovate or oblong, 0.7-4.5 cm wide, the margins entire and plane.
• 16. Staminate bracts 1-1.6 mm long; anthers 1.3-1.7 mm long; in our area in SW Idaho and SW Utah; Washington county. Amaranthus tuberculatus

Amaranthus tuberculatus	Amaranthus tuberculatus	Amaranthus tuberculatus

• 16' Staminate bracts 2.7-6 mm long; anthers 1-1.4 mm long; in W U.S. from California, S Nevada, SW Utah and Colorado, southward; Washington, San Juan counties. Amaranthus palmeri

Amaranthus palmeri	Amaranthus palmeri

• 15' Leaves linear to narrowly lanceolate, 0.1-0.7-(1) cm wide, the margins crispate to irregularly undulate; S Utah, southward; Kane county. Amaranthus acanthochiton

Amaranthus acanthochiton	Amaranthus acanthochiton

• 1' Stems prostrate to spreading-ascending; glomerules axillary only, rarely in terminal spikes or panicles; bracts small and inconspicuous; fruits indehiscent (utricles), irregularly dehiscent, or circumscissile (capsules).
• 17. Apex of the leaves, at least the middle and upper ones, broadly retuse, sometimes nearly bilobate; bracts about 0.5 mm long; Utah county. Amaranthus blitum

Amaranthus blitum	Amaranthus blitum	Amaranthus blitum

• 17' Apex of the leaves obtuse to rounded, rarely shallowly emarginate; bracts 1-4 mm long.
• 18. Inflorescences axillary only.
• 19. Capsules 1-1.7 mm long, 1-1.2 mm wide, subglobose, tardily dehiscent, sometimes circuscissile; seed 0.9-1.2 mm long, suborbicular; pistillate sepals 1-3, 0.8-1.5 mm long.
• 20. Bracts inconspicuous, 1-2 mm long; leaves 0.5-1.2-(1.7) cm long, 2.5-8-(10) mm wide; herbage glabrous; in our area in SE Oregon, Nevada, S Idaho and Utah (Box Elder, Cache, Washington counties). Amaranthus californicus

Amaranthus californicus	Amaranthus californicus	Amaranthus californicus	Amaranthus californicus

• 20' Bracts 2-3.5 mm long; leaves 1-3.2 cm long, 4-17 mm wide; herbage papillate-puberulent; widespread but not common. Amaranthus albus

Amaranthus albus	Amaranthus albus

• 19' Capsules 1.8-2.8 mm long, 1.5-1.6 mm wide, ovoid to ellipsoid, with circumscissile dehiscence; seed 1.1-1.7 mm long, broadly obovate; pistillate sepals 4 or 5, 1.4-3.4 mm long. Amaranthus blitoides

Amaranthus blitoides	Amaranthus blitoides	Amaranthus blitoides	Amaranthus blitoides

• 18' Inflorescences terminal and axillary, the terminal ones often well developed.
• 21. Fruit 2-3 mm long, 1.3-1.5 mm wide, somewhat inflated, indehiscent; seed 1-1.1 mm long; staminate sepals 2 or 3, 1.3-1.7 mm long; pistillate sepals 2(3), (1.4)-1.9-2.2 mm long; anthers 0.4-0.6 mm long; in our area in SW Utah; Washington county. Amaranthus deflexus

Amaranthus deflexus	Amaranthus deflexus

• 21' Fruit 1-1.5 mm long, 0.7-1 mm wide, not inflated, mostly indehiscent, sometimes irregularly dehiscent or circumscissile; seed 0.7-0.9 mm long; staminate sepals 5, 2-3.5 mm long; pistillate sepals lacking, or 1-2 rudimantary ones, no longer than 1.5 mm; anthers 1.3-1.7 mm long; in our area in SW Idaho and SW Utah; Washington county. Amaranthus tuberculatus

Amaranthus tuberculatus	Amaranthus tuberculatus	Amaranthus tuberculatus