The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

blood amaranth, caterpillar amaranth, purple amaranth, red amaranth

African amaranth, muricate amaranth

Habit Plants almost glabrous or slightly pubescent distally, especially when young. Plants annual or short-lived perennial, glabrous or slightly pubescent near tips.
Stems

erect, green or reddish purple, branched distally, mostly in inflorescence, to nearly simple, 0.4–2 m. Leaves: petiole 1/2 as long as to ± equaling blade;

blade rhombic-ovate or ovate to broadly lanceolate, 3–15(–20) × 1.5–10(–15) cm, occasionally larger in robust plants, base cuneate to broadly cuneate, margins entire, plane, apex acute or subobtuse to slightly emarginate, with mucro.

ascending or prostrate, much-branched from stout rootstock, 0.1–0.4 m. Leaves: petiole to 1/2 as long as blade;

blade linear to narrowly lanceolate, 1.5–8 × 0.2–0.5(–1) mm, base tapering, margins entire, plane to undulate, apex obtuse and often emarginate.

Bracts

narrowly spathulate, 2–3 mm, equaling or slightly longer than tepals, apex short-spinescent.

of pistillate flowers linear, 0.7–1.2 mm, 1/2–2/3 as long as tepals.

Inflorescences

terminal and axillary, erect, reflexed, or nodding, usually dark red, purple, or deep beet-red, less commonly almost green or greenish red, leafless at least distally, large and robust.

terminal, compact pyramidal panicles and axillary glomerules, erect or reflexed, green, leafless at least distally.

Staminate flowers

at tips of inflorescences;

tepals 5;

stamens (4–)5.

intermixed with pistillate or at tips of inflorescences;

tepals 5;

stamens 5.

Pistillate flowers

tepals 5, oblong to lanceolate, not clawed, equal or subequal, 1.5–3 mm, apex acute;

style branches erect or slightly reflexed;

stigmas 3.

tepals 5, narrowly oblanceolate, not clawed, equal, 1.5–2 mm, apex obtuse or subacute;

style branches erect;

stigmas 3.

Seeds

usually white or ivory, with reddish or yellowish tint, sometimes dark brown to dark reddish brown, broadly lenticular to elliptic-lenticular, 1.2–1.6 mm diam., smooth or indistinctly punctate.

black, lenticular, 1–1.2 mm diam., semiglossy.

Utricles

obovoid to elongate-obovoid, 2–2.5 mm, smooth or slightly rugose distally, dehiscence regularly circumscissile.

compressed, subglobose, 1.7–2 mm, ± equaling or slightly exceeding tepals, muricate, indehiscent.

Amaranthus cruentus

Amaranthus muricatus

Phenology Flowering summer–fall. Flowering summer–fall.
Habitat Near places of cultivation Waste places, on ballast
Elevation 0 m (0 ft)
Distribution
from FNA
AZ; CA; CT; IL; IN; KY; MA; MD; ME; MI; NC; NE; NH; NJ; NY; OH; OR; PA; RI; SC; TX; UT; VT; WA; WI; WV; Central America; South America; cultivated widely
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; s South America (Argentina, Paraguay, Uruguay) [Introduced in North America; introduced in s Europe, s Africa, Australia, and other regions]
[BONAP county map]
Discussion

Amaranthus cruentus is cultivated as ornamental and pseudocereal almost worldwide from tropical to warm-temperate regions. While reported as naturalized in several states, most specimens identified as this species are referable to A. hybridus or other native species. Escaped plants of A. cruentus sometimes occur near places of cultivation (see note under A. caudatus). No attempt has been made to summarize distribution data for such escapes.

Amaranthus cruentus originated from A. hybridus (most probably in cultivation in Central America), with which it shares almost all major morphologic characteristics. Inclusion of cultivated forms in A. hybridus in a broad sense is thus rather justified. Cultivated species traditionally have been treated as separate taxa in horticultural and agricultural literature, and we prefer to maintain the current convenient usage of these names.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

The vernacular name “African amaranth” is sometimes used for this species; it is a misnomer; the species is native to South America and naturalized in Africa.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 4. FNA vol. 4, p. 431.
Parent taxa Amaranthaceae > Amaranthus > subg. Amaranthus Amaranthaceae > Amaranthus > subg. Albersia
Sibling taxa
A. acanthochiton, A. albus, A. arenicola, A. australis, A. blitoides, A. blitum, A. californicus, A. cannabinus, A. caudatus, A. crassipes, A. crispus, A. deflexus, A. dubius, A. fimbriatus, A. floridanus, A. graecizans, A. greggii, A. hybridus, A. hypochondriacus, A. muricatus, A. obcordatus, A. palmeri, A. polygonoides, A. powellii, A. pumilus, A. retroflexus, A. scleropoides, A. spinosus, A. tamaulipensis, A. thunbergii, A. torreyi, A. tricolor, A. tuberculatus, A. viridis, A. viscidulus, A. watsonii, A. wrightii
A. acanthochiton, A. albus, A. arenicola, A. australis, A. blitoides, A. blitum, A. californicus, A. cannabinus, A. caudatus, A. crassipes, A. crispus, A. cruentus, A. deflexus, A. dubius, A. fimbriatus, A. floridanus, A. graecizans, A. greggii, A. hybridus, A. hypochondriacus, A. obcordatus, A. palmeri, A. polygonoides, A. powellii, A. pumilus, A. retroflexus, A. scleropoides, A. spinosus, A. tamaulipensis, A. thunbergii, A. torreyi, A. tricolor, A. tuberculatus, A. viridis, A. viscidulus, A. watsonii, A. wrightii
Synonyms A. hybridus subsp. cruentus Euxolus muricatus
Name authority Linnaeus: Syst. Nat. ed. 10, 2: 1269. (1759) (Moquin-Tandon) Hieronymus: Pl. Diaph. Fl. Argent., 227. (1882)
Web links