Practical ecological knowledge for the temperate reader.

Amaranthus Sp. - Pigweed

Family: Amaranthaceae - Amaranth [E-flora]

Annual (short-lived perennial herb); monoecious or dioecious. [Jepson]

"+/- 70 species: worldwide; weeds, ornamentals, food plants. (Greek: unfading, non-withering) [Costea et al. 2001 Sida 19:931–974, 975–992; Sauer 1967 Ann Missouri Bot Gard 54:103–137] Hybrids common, F1 generally with numerous, densely packed bractlets beneath generally sterile pistillate flowers, abnormal-shaped inflorescence with dense, twisted or fan-shaped branches. Unless otherwise noted, descriptions of bracts and flower parts are of pistillate flowers.
Unabridged references: [Sauer 1955 Madroño 13:5–46]
Unabridged note: F1 hybrids have been observed in natural conditions or have been experimentally obtained between any of the following species: Amaranthus hybridus, Amaranthus powellii, Amaranthus retroflexus, Amaranthus tuberculatus, Amaranthus palmeri, Amaranthus caudatus, Amaranthus hypochondriacus, Amaranthus cruentus, Amaranthus spinosus, Amaranthus blitoides, Amaranthus albus. Amaranthus caudatus L., Amaranthus cruentus L., Amaranthus hypochondriacus L. frequently cultivated as ornamentals, occasionally escaping from cultivation. Amaranthus spinosus L. probably not naturalized, uncommon waif."[Jepson]

Local Species;

  1. Amaranthus albus - Tumbleweed [E-flora]
  2. Amaranthus blitoides - Prostrate Pigweed [E-flora]
  3. Amaranthus blitum - Purple amaranth [E-flora]
  4. Amaranthus powellii - Powell's Amaranth [E-flora]
  5. Amaranthus retroflexus - Rough Pigweed [E-flora]

Uses of Other Amaranthus sp.

"The seeds of Amaranthus sp. (Amaranth) and Chenopodium quinoa (Quinoa) are edible and used as pseudocereals." [Mroczek, Agnieszka, 2015]

Amaranthus hybridus "Red Amaranth, or Prince's Feather, Amaranthus hybridus, a weed in waste and cultivated grounds, is found over most of North America. It is cultivated in India for its seeds, which are eaten and used as a potherb in the West Indies. Its seeds are eaten by Indians of the Southwest." [EWP]


Amaranthus sp. - Amaranthaceae


  • ALANINE Leaf 1390 16722 DUKE1992A
  • ARGININE Leaf 1210 14556 DUKE1992A
  • ASCORBIC-ACID Leaf 345 6263 DUKE1992A
  • ASPARTIC-ACID Leaf 2290 27549 DUKE1992A
  • BETA-CAROTENE Leaf 0 508 DUKE1992A
  • CALCIUM Leaf 1559 53333 DUKE1992A
  • CARBOHYDRATES Leaf 40300 540000 DUKE1992A
  • COPPER Leaf 1 19 DUKE1992A
  • CYSTINE Leaf 290 3489 DUKE1992A
  • FAT Leaf 2410 53000 DUKE1992A
  • FIBER Leaf 8830 135000 DUKE1992A
  • FOLACIN Leaf 1 10 DUKE1992A
  • GLUTAMIC-ACID Leaf 2920 35128 DUKE1992A
  • GLYCINE Leaf 1320 15880 DUKE1992A
  • HISTIDINE Leaf 520 6256 DUKE1992A
  • IRON Leaf 23 1527 DUKE1992A
  • ISOLEUCINE Leaf 1190 14316 DUKE1992A
  • LEUCINE Leaf 1950 23458 DUKE1992A
  • LYSINE Leaf 1270 15278 DUKE1992A
  • MAGNESIUM Leaf 550 6616 DUKE1992A
  • METHIONINE Leaf 360 4331 DUKE1992A
  • NIACIN Leaf 6 118 DUKE1992A
  • PHENYLALANINE Leaf 1330 16000 DUKE1992A
  • PHOSPHORUS Leaf 487 10082 DUKE1992A
  • POTASSIUM Leaf 2630 73503 DUKE1992A
  • PROLINE Leaf 1210 14556 DUKE1992A
  • PROTEIN Leaf 22850 342000 DUKE1992A
  • RIBOFLAVIN Leaf 1 26 DUKE1992A
  • RUTIN Plant DUKE1992A
  • SERINE Leaf 1110 13353 DUKE1992A
  • SODIUM Leaf 110 2406 DUKE1992A
  • THIAMIN Leaf 1 7 DUKE1992A
  • THREONINE Leaf 990 11910 DUKE1992A
  • TRYPTOPHAN Leaf 310 3729 DUKE1992A
  • TYROSINE Leaf 800 9624 DUKE1992A
  • VALINE Leaf 1370 16481 DUKE1992A
  • WATER Leaf 916000 DUKE1992A
  • ZINC Leaf 9 108 DUKE1992A

"Sugars in Amaranthaceae saponins are linked to the aglycone at the C-3 or/and C-28, but C-23 glycosides can be also encountered. Most of the Amaranthaceae saponins possess bisdesmosidic structure and so far only one tridesmosidic saponin was isolated from Amaranthus caudatus (Rastrelli et al. 1995)." [Mroczek, Agnieszka, 2015]

"Differences, although subtle, could be observed also in Amaranthus genus. Saponins from A. hypochondriacus (Kohda et al. 1991), A. caudatus (Rastrelli et al. 1995) and A. cruentus (Oleszek et al. 1999) possess common structural features.... However, they differ in the oxidation pattern at C-23 and C-6 aswell as in the composition of the oligosaccharide chain at C-3. Aglycones with the –CH3, –CH2OH or –CHO group at C-23 were described in A. hypochondriacus (Kohda et al. 1991), whereas aglycones with a –COOH group present atC-23 and a –OH group at C-6 were found in A. caudatus (Rastrelli et al. 1995) and in A. cruentus (Oleszek et al. 1999). Although saponins from a particular genera posses similar pattern, some differences can be observed between the plants from the same genus. Thus, studies on Amaranthaceae phytochemicals have revealed that the chemical composition of saponins can vary regardless of the very close systematic relationship." [Mroczek, Agnieszka, 2015]

Amaranthus albus - Tumbleweed

General: "Annual herb from a taproot; stems erect or ascending, several, glabrous to short-hairy, branching basally forming a rounded plant to 1 m tall, tending to break off at the base at maturity and then behaving as a "tumbleweed"." [IFBC-E-flora]

Habitat / Range: "Dry disturbed areas and waste places in the montane zone; infrequent in S BC; throughout N. America, S. America and the Old World." [IFBC-E-flora]

Status: Exotic [E-flora]

Amaranthus blitoides - Prostrate Pigweed

General: "Annual herb from a taproot; stems prostrate or decumbent, several, glabrous to short-hairy, 30-70 cm tall." [IFBC-E-flora]

Habitat / Range: "Dry disturbed areas in the lowland, steppe and montane zones; infrequent in S BC; throughout N. America, W. Indies, Europe." [IFBC-E-flora]

Prostrate Amaranth, Amaranthus blitoides, which is found as a weed from Maine to North Dakota, south to New Jersey, Missouri, and Kansas, and is native west of the Rocky Mountains. [EWP]

Status: Exotic [E-flora]

Edible Uses


Amaranthus powellii - Powell's Amaranth

Local Subtaxa:

General: "Annual herb from a taproot; stems erect, simple to freely branched, 0.3-2.0 m tall, grooved, often reddish, glabrous to short-hairy or sparsely hairy below the flowers." [IFBC-E-flora]

Habitat / Range: "Moist to dry fields, disturbed areas and waste places; infrequent in SW and SC BC, known from the Gulf Islands, the Vancouver area and the Okanagan Valley; throughout N. America, S. America and the Old World." [IFBC-E-flora]

Amaranthus retroflexus - Rough Pigweed

General: "Annual herb; stems 50-100 cm tall, simple to freely branched, long-hairy with dandruff-like scales below the flowers." [IFBC-E-flora]

Similar Species:

"The redroot amaranth can be easily mistaken for other pigweeds, mostly for the Powell’s amaranth (Amaranthus powellii), which it resembles with its spikelike, elongated inflorescence. What separates them is mostly the conspicuous hairiness of the stems and leaves of the redroot amaranth, as opposed to the scarcely (if at all) hairy Powell’s amaranth. When young or under poor growing conditions, the redroot amaranth might resemble the other two introduced pigweeds, the mat amaranth (Amaranthus blitoides) and white pigweed (Amaranthus albus). In these species, though, the leaves are much smaller and the inflorescences develop in small clusters in the axils of the leaves."

"Some of the members of the Goosefoot (Chenopodiaceae) family might be mistaken from a distance for the redroot amaranth, such as lamb’s quarters (Chenopodium album) or French spinach (Atriplex hortensis). However, these plants have smoother and thinner leaves, mostly wavy, all being hairless and powdery. Their inflorescences are not prickly, as in the redroot amaranth, but rather fleshy in the lamb’s quarters or sandwiched between a pair of leafy bracts in the French spinach."

"The redroot amaranth might occasionally be mistaken for the red-listed wedgescale saltbush (Atriplex truncata), which can grow in similar habitat conditions, in dry roadsides and waste places. It has wedged and greenish inflorescences, but they develop in the axils of the leaves. This species can be easily differentiated based on the grayish, not grass-green leaves. The whole plant is mealy coated and much more slender than the redroot amaranth."

Note Author Anna-Mária Csergo, February 2011. [E-flora]

Habitat / Range: "Moist to dry fields, disturbed areas and waste places in the lowland, steppe and montane zones; frequent in S BC, rare northward; throughout N. America and the Old World." [IFBC-E-flora]

Edible Uses

"Main dish: Plants such as Amaranthus retroflexus L., F. vulgare, C. intybus and C. arvense are cooked with onion, tomato paste, oil, meat, mushroom, chicken and water. Again as flavorings, spices like peppermint, Thymus sp., black pepper, and red pepper are added." [dogan2004]

Medicinal Uses



Redroot AmaranthAmaranthus Retroflexus

Part:LeafPer 100 g fresh weight (water content not given)
Food Energy (Kcal)35Ash (g)-Potassium (mg)411-617
Water (g)-Thiamine (mg)-Magnesium (mg)-
Protein (g)-Riboflavin (mg)-Calcium (mg)267-448
Fat (g)-Niacin (micrograms)1,300Phosphorus (mg)-
Carbohydrate (g)-Vitamin C (mg)53-80Sodium (mg)-
Crude Fiber (g)-Vitamin A (micrograms)4,300Iron (mg)-
Zinc (mg)-Manganese (mg)-Copper (mg)-

Redroot AmaranthAmaranthus Retroflexus

Part:SeedPer 100 g fresh weight (water content not given)
Food Energy (Kcal)358Ash (g)-Potassium (mg)52.5
Water (g)-Thiamine (mg)-Magnesium (mg)-
Protein (g)-Riboflavin (mg)-Calcium (mg)247
Fat (g)-Niacin (mg)-Phosphorus (mg)500
Carbohydrate (g)-Vitamin C (mg)-Sodium (mg)-
Crude Fiber (g)-Vitamin A (RE)-Iron (mg)-
Zinc (mg)-Manganese (mg)-Copper (mg)-


Phytoremediation: Amaranthus retroflexus showed high bioaccumulations factors but showed low biomass compared to other species and thus weak phytoextraction. Pesticide concentration decreased in the rhizosphere soil 11-24% more in treatments with fertilizer compared to treatments without fertilizer.[OPPPS]


Page last modified on Friday, January 21, 2022 1:46 AM