Amaranthus macrocarpus — dwarf amaranth
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Facts
Dwarf amaranth owes its name to being smaller than other amaranths (Amaranthus). However, the Latin specific (macrocarpus) refers to the fact that it also has larger fruits compared to other amaranths. The fruits are also warty and wrinkled.
Habitat
Anthropogenic (man-made or disturbed habitats)
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
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enlargeCharacteristics
- Habitat
- terrestrial
- New England state
- Massachusetts
- 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)
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Fusion of sepals and petals
- both the petals and sepals are separate and not fused
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit length
- 1.5–2 mm
-
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 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
- 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 symmetry
-
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Flowers sunken into stem
- no
- Form of style
-
- NA
- the style is unbranched, but it has two or more narrow appendages that are part of the stigma
- 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
- Inflorescence one-sided
- the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
- Inner tepals (Rumex)
- NA
- Nectar spur
- the flower has no nectar spurs
- Number of pistils
-
- 0
- 1
- 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 folds or pleats
- NA
- Petal hairs (Viola)
- NA
- Petal number
- 0
- Petal tip shape
- NA
- Petal tips (Cuscuta)
- 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 appendages
- the sepals do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Stamen attachment
-
- NA
- the stamens are not attached to the petals or tepals
- the stamens are not attached to the petals or tepals
- Stamen position relative to petals
-
- NA
- the stamens are lined up with the sepals
- Staminodes
- there are no staminodes on the flower
- 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 features (Brassicaceae)
- NA
- Fruit length
- 1.5–2 mm
- Fruit locules
- one
- 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)
- 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
- 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
- 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
-
Leaves
- Bracteole number (Apiaceae)
- 0
- 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
- 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 edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- 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 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 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).
- 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 features
- NA
- Stipules
- there are no stipules on the plant
-
Place
- Habitat
- terrestrial
- New England state
- Massachusetts
- Specific habitat
- man-made or disturbed habitats
-
Stem, shoot, branch
- Branched tendrils
- NA
- Hooked hairs on stem between nodes
- no
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Stem roughness between nodes
- the stem does not feel rough
- Tendril origin
- NA
- Tendrils
- the plant does not have tendrils
Wetland status
Not classified
In New England
Distribution
- Connecticut
- absent
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- absent
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
var. macrocarpus
- Massachusetts
- not applicable (S-rank: SNA)
Subspecies and varieties
Our variety is Amaranthus macrocarpus Benth. var. macrocarpus.
From Flora Novae Angliae dichotomous key
11. Amaranthus macrocarpus Benth. var. macrocarpus E
dwarf amaranth. Euxolus macrocarpus (Benth.) F. Muell. • MA. Wool waste.
Native to North America?
No
Sometimes confused with
- Amaranthus albus:
- fruit neither warty nor rugose, not or barely exceeding the sepals (vs. A. macrocarpus, with fruit warty-rugose, exceeding the sepals).
Synonyms
- Euxolus macrocarpus (Benth.) F. Muell.