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Native Plant Trust: Go Botany Discover thousands of New England plants

Amaranthus retroflexus — red-rooted amaranth

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Facts

Red-rooted amaranth is native to North America and introduced nearly worldwide. In New England it is mainly found in human-disturbed, sandy soils. The young leaves and seeds are edible, and were used for food by many Native American tribes.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields, shores of rivers or lakes

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Flower petal color
NA
Leaf type
the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
Leaf arrangement
alternate: there is one leaf per node along the stem
Leaf blade edges
the edge of the leaf blade is entire (has no teeth or lobes)
Flower symmetry
there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
Number of sepals, petals or tepals
there are five petals, sepals, or tepals in the flower
Fusion of sepals and petals
both the petals and sepals are separate and not fused
Stamen number
  • 3
  • 4
  • 5
Fruit type (general)
the fruit is dry and splits open when ripe
Fruit length
1.5–2.5 mm
Show all characteristics

  • Clonal plantlets

    Bulbils
    the plant does not appear to have bulbils
    Bulblets replace flowers
    there are no bulblets where the flowers are located

  • Flowers

    Anther attachment
    the anther is attached near its midpoint to the filament
    Anther color
    the anthers show no hint of a pink, reddish or purplish tint
    Anther length
    0.9–1 mm
    Anther opening
    the anthers have narrow slits or furrows that run lengthwise along the anthers
    Anther spurs
    the anthers do not have spurs on them
    Calyx symmetry
    there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)
    Carpels fused
    the carpels are fused to one another
    Cilia on petals
    NA
    Cleistogamous flowers
    there are no cleistogamous flowers on the plan
    Corolla morphology
    NA
    Corolla palate
    NA
    Corona lobe length
    0 mm
    Epicalyx
    the flower does not have an epicalyx
    Epicalyx number of parts
    0
    Filament surface
    the filament is smooth, with no hairs or scales
    Flower description
    the flower has a superior ovary, and lacks a hypanthium
    Flower petal color
    NA
    Flower reproductive parts
    the flower has either only pollen- or only seed-producing parts
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Flowers sunken into stem
    no
    Form of style
    the style is lobed at the tip, and unbranched
    Fringed petal edges
    NA
    Fusion of sepals and petals
    both the petals and sepals are separate and not fused
    Horns in hoods (Asclepias)
    NA
    Hypanthium
    the flower does not have a hypanthium
    Hypanthium length
    0 mm
    Inflorescence length
    20–300 mm
    Inflorescence one-sided
    the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
    Inflorescence width
    10–50 mm
    Inner tepals (Rumex)
    NA
    Marks on petals
    NA
    Nectar spur
    the flower has no nectar spurs
    Number of branches in umbel
    0
    Number of carpels
    2–4
    Number of pistils
    1
    Number of sepals, petals or tepals
    there are five petals, sepals, or tepals in the flower
    Number of styles
    3
    Ovary position
    the ovary is above the point of petal and/or sepal attachment
    Petal and sepal arrangement
    the flower includes only one cycle of petals or sepals
    Petal and sepal colors
    green to brown
    Petal appearance
    NA
    Petal base
    NA
    Petal folds or pleats
    NA
    Petal glandular dots or scales
    NA
    Petal hairs (Viola)
    NA
    Petal hairs on inner/upper surface
    NA
    Petal length
    0 mm
    Petal length relative to sepals
    NA
    Petal nectaries
    NA
    Petal number
    0
    Petal shape
    NA
    Petal tip shape
    NA
    Petal tips (Cuscuta)
    NA
    Petal width
    0 mm
    Raceme attachment (Veronica)
    NA
    Reproductive system
    each flower has only carpels or only stamens, but both types of flower are present on each plant (monoecious)
    Scales inside corolla
    NA
    Sepal and petal color
    NA
    Sepal appearance
    the sepals are green or brown, and leaf-like in texture
    Sepal appendages
    the sepals do not have appendages on them
    Sepal appendages (Oenothera)
    NA
    Sepal color
    • green to brown
    • other
    • pink to red
    Sepal length
    2–4 mm
    Sepal number
    5
    Sepal orientation
    • the sepals are pressed against the corolla, or jutting stiffly upward
    • the sepals are slightly curved outwards from the corolla
    Sepal relative length
    NA
    Sepal shape
    • the sepal outline is lanceolate (lance-shaped; narrow, gradually tapering from the base to the tip)
    • the sepal outline is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
    • the sepal outline is spatulate (roughly spoon-shaped; narrow near the base, suddenly widening to a rounded tip)
    Sepal texture
    the sepals are thin and dry, paperlike
    Sepal tip shape
    the sepal tip is obtuse (is bluntly pointed)
    Sepals fused only to sepals
    the sepals are separate from one another
    Stamen attachment
    the stamens are not attached to the petals or tepals
    Stamen number
    • 3
    • 4
    • 5
    Stamen position relative to petals
    the stamens are lined up with the sepals
    Stamen relative length
    anything
    Stamens fused
    the stamens are not attached to one another
    Staminodes
    there are no staminodes on the flower
    Stigma length
    0.7–0.9 mm
    Style length
    0.1–1 mm
    Style petal-like
    the styles are not petal-like
    Umbel flower reproductive parts
    NA
    Upper lip of bilabiate corolla
    NA

  • Fruits or seeds

    Achene relative orientation
    NA
    Achene shape
    NA
    Achene surface (Polygonum)
    NA
    Achene type
    NA
    Berry color
    NA
    Capsule color (Viola)
    NA
    Capsule ribs
    NA
    Capsule splitting
    NA
    Fruit (pyxis) dehiscence
    the pyxis splits on or near the middle
    Fruit cross-section
    the fruit is at least somewhat flattened
    Fruit features (Brassicaceae)
    NA
    Fruit length
    1.5–2.5 mm
    Fruit length relative to sepals
    the fruit is shorter than its associated sepals
    Fruit locules
    one
    Fruit shape
    • the fruit is ellipsoid (widest in the middle and tapering to each end)
    • the fruit is obovoid (egg-shaped, but with the widest point above the middle)
    Fruit type (general)
    the fruit is dry and splits open when ripe
    Fruit type (specific)
    the fruit is a pyxis (when dry it splits around the middle, and the top falls off, exposing the seeds)
    Fruit width
    1–1.3 mm
    Hair type on fruit
    NA
    Hairs on fruit
    the fruits are not hairy
    Legumes (Fabaceae)
    NA
    Mericarp length
    0 mm
    Mericarp segment shape (Desmodium)
    NA
    Other markings on berry
    NA
    Ovary stipe
    the ovary or fruit does not have a stipe
    Placenta arrangement
    the plant has basal placentation, where one or a few ovules develop at the base of a simple or compound ovary
    Rows of seeds in fruit (Brassicaceae)
    NA
    Schizocarpic fruit compression
    NA
    Schizocarpic fruit segments
    0
    Seed length
    1–1.3 mm
    Seed number
    1
    Seed relative length
    the seed is about as long as it is wide
    Seed surface
    the seed is smooth or without clear markings
    Seeds comose
    no hairs
    Septum in fruit (Brassicaceae)
    NA
    Wings on fruit
    the fruit does not have wings on it
    prickles on fruits
    the fruits do not have thorn-like defensive structures

  • Glands or sap

    Glands on leaf blade
    the leaf blades do not have glandular dots or scales
    Sap
    the sap is clear and watery
    Sap color
    the sap is clear

  • Growth form

    Growth form
    the plant is an herb (it has self-supporting stems)
    Horizontal rooting stem
    the plant does not have stolons
    Lifespan
    the plant lives only a single year or less
    Parasitism
    the plant is not parasitic
    Plant color
    the leaves or young stems of the plant are green
    Plants darken when dry
    no
    Spines on plant
    the plant has no spines
    Underground organs
    there is a thickened taproot on the plant

  • Leaves

    Bracteole edges
    • the bracteole margins are entire (without teeth, lobes or hairs)
    • the bracteole margins have teeth
    Bracteole length
    3–6 mm
    Bracteole number (Apiaceae)
    0
    Bracteole shape
    the bracteoles are subulate (narrowly tapering from the base to the apex; awl-shaped)
    Bracteoles
    • the plant has bracteoles between the primary bracts and the flowers
    • there are no bracteoles on the plant
    Bracts in plantain (Plantago)
    NA
    Final leaf segment length (compound lvs only)
    0 mm
    Final leaf segment length to width ratio (compound lvs only)
    0
    Final leaf segment width (compound lvs only)
    0 mm
    Floral bract texture
    the floral bracts are thin, dry and papery, possibly with a narrow green stripe at the center
    Floral bracts
    the flower has one or more bracts associated with it
    Flower bract length
    2.5–6 mm
    Hairs on leaf stalk
    the petiole has hairs on it
    Hairs on underside of leaf
    the underside of the leaf is fuzzy or hairy
    Hairs on upper side of leaf
    the upper side of the leaf is fuzzy or hairy
    Hooked hairs on underside of leaf
    no
    Inflated hairs on leaf
    the leaf blade does not have inflated hairs on it
    Leaf arrangement
    alternate: there is one leaf per node along the stem
    Leaf blade base
    the leaf has a distinct leaf stalk (petiole)
    Leaf blade base shape
    • the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
    • the base of the leaf blade is rounded
    Leaf blade bloom
    the underside of the leaf has no noticeable bloom
    Leaf blade edges
    the edge of the leaf blade is entire (has no teeth or lobes)
    Leaf blade flatness
    the leaf is flat (planar) at the edges
    Leaf blade hairs
    the leaf blade has simple hairs with no glands, and not tangled or wooly
    Leaf blade length
    20–150 mm
    Leaf blade primary vein pattern
    the secondary veins branch off at intervals from the primary vein
    Leaf blade shape
    • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
    • the leaf blade is rhombic (roughly diamond-shaped)
    Leaf blade surface colors
    the upper side of the leaf blade is relatively uniform in color
    Leaf blade vein pattern
    the major veins of the leaf blade branch, but do not rejoin
    Leaf blade veins
    the leaf blade has one main vein running from the base towards the tip (it may or may not have secondary veins)
    Leaf blade width
    10–70 mm
    Leaf duration
    the leaves drop off in winter (or they whither but persist on the plant)
    Leaf form
    the leaves are green, with an expanded blade and a leaf-like texture
    Leaf spines
    there are no spines on the leaf edges
    Leaf stalk
    the leaves have leaf stalks
    Leaf stalk attachment to leaf
    the petiole attaches at the basal margin of the leaf blade
    Leaf stalk base
    the petiole base clasps the stem or sheathes the stem
    Leaf stalk length
    15–55 mm
    Leaf teeth and lobes
    • the edge of the leaf blade is entire (has no teeth or lobes)
    • the leaf blade margin is wavy, but does not have teeth
    Leaf tip
    • the tip of the leaf blade is acute (sharply pointed)
    • the tip of the leaf blade is obtuse (bluntly pointed)
    Leaf type
    the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
    Leaf types
    There is a gradual change in appearance of the leaves from the base (or near the base) of the plant to those from further up on the stem, with leaves progressively changing as one moves higher on the stem (often becoming shorter, or less toothed/lobed, and/or with shorter petioles).
    Leaf variation
    the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
    Leaflet number
    0
    Leaflet petiolules
    NA
    Leaves per node
    there is one leaf per node along the stem
    Pinnately compound leaf type
    NA
    Specific leaf type
    the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
    Stipels
    NA
    Stipule edges
    NA
    Stipule features
    NA
    Stipule fused to leaf stalk
    NA
    Stipule length
    0 mm
    Stipule shape
    NA
    Stipules
    there are no stipules on the plant
    Teeth per side of leaf blade
    0

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
    • shores of rivers or lakes

  • Stem, shoot, branch

    Branched tendrils
    NA
    Direction of stem hairs
    the hairs point mostly upwards to outwards
    Flowering stem cross-section
    the flowering stem is circular, or with lots of small angles so that it is roughly circular
    Hair between stem nodes
    the stem has hairs between the nodes
    Hairs between stem nodes
    the hairs on the stem are plain, without glands or branches, and not tangled
    Hooked hairs on stem between nodes
    no
    Leaves on stem
    there is at least one full leaf above the base of the flowering stem
    Plant height
    20–200 cm
    Stem hair distribution
    the hairs on the stem are distributed more of less uniformly
    Stem orientation
    the stems are upright or angled outwards
    Stem roughness between nodes
    the stem feels rough due to hairs or prickles
    Stem succulence
    the stems are not succulent
    Tendril origin
    NA
    Tendrils
    the plant does not have tendrils
    Wings on stem
    the stem does not have wings on it

Wetland status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

In New England

Distribution

Connecticut
present
Maine
present
Massachusetts
present
New Hampshire
present
Rhode Island
present
Vermont
present

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
not applicable (S-rank: SNA)

From Flora Novae Angliae dichotomous key

15.  Amaranthus retroflexus L. N

red-rooted amaranth. Amaranthus retroflexus L. var. salicifolius I.M. Johnston • CT, MA, ME, NH, RI, VT. Gardens, fields, roadsides, waste areas, disturbed sandy soils, sandy shorelines.

Native to North America?

Yes

Sometimes confused with

Amaranthus hybridus:
sepals of fruit-bearing flowers acute at apex and inflorescence with many, short, croweded, thick branches of flowers (vs. A. retroflexus, with sepals of fruit-bearing flowers rounded to truncate at apex and inflorescence with few to many, slender, lax branches of flowers).
Amaranthus powellii:
sepals of fruit-bearing flowers acute at apex and inflorescence with few, rigid, widely spaced branches of flowers (vs. A. retroflexus, with sepals of fruit-bearing flowers rounded to truncate at apex and inflorescence with few to many, slender, lax branches of flowers).

Synonyms

  • Amaranthus retroflexus var. salicifolius I.M. Johnston

Family

Amaranthaceae

Genus

Amaranthus