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- Alliaceae
- Allium
- Allium cepa
Allium cepa — garden onion
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Facts
Garden onion is cultivated worldwide. Although it there is no known wild progenitor, the nearest wild relative is Allium oschanini, a species from central Asia. There are many cultivars of onion, with a wide range of morphologies, including some with bulbils in the inflorescence. Garden onion may escape within areas of cultivation or agriculture, and occurs sporadically across North America, including New England.
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields
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.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Leaf arrangement
- basal: the leaves are growing only at the base of the plant
- Leaf blade shape
- the leaf blade is linear (very narrow with more or less parallel sides)
- Leaf blade length
- 100–500 mm
- Flower petal color
-
- pink to red
- white
- Flower petal length
- 3–4.5 mm
- Petal fusion
- the perianth parts are separate
- Inflorescence type
- the inflorescence is an umbel (with an axis so short it appears the flowers all originate from the same point)
- Ovary position
- the ovary is above the point of petal and/or sepal attachment
- Fruit type (specific)
- the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)
- Fruit length
- Up to 5 mm
-
Clonal plantlets
- Axillary bulblets
- there are no bulblets being produced in axils
-
Flowers
- Anther attachment
- the anther is attached by its base to the filament
- Anther color
- the anthers show no hint of a pink, reddish or purplish tint
- Bulblets replace flowers
- there are no bulblets where the flowers are located
- Carpels fused
- the carpels are fused (the number of carpels equals the number of locules)
- Filament surface
- the filament surface has no hairs or scales on it
- Flower bracts
- there are bracts associated with the flower
- Flower number
- Up to 500
- Flower orientation
- the flowers point upward or spread or curve outward
- Flower petal color
-
- pink to red
- white
- Flower petal length
- 3–4.5 mm
- Flower shape
-
- the flower has an urn-shaped corolla (constricted at the opening)
- the flower is bell-shaped
- Flower symmetry
- there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
- Flowering stem width
- 3–20 mm
- Form of style
- the style is knob-like at the tip, and unbranched
- Fringed petal edges
- the petals are not fringed
- Hairs on flower stalk
- the flower stalk has no hairs on it
- Inflorescence hair glands
- the axis of the inflorescence has no hairs on it
- Inflorescence length
- 300–1000 mm
- Inflorescence type
- the inflorescence is an umbel (with an axis so short it appears the flowers all originate from the same point)
- Inflorescence width
- 3–20 mm
- Length of flower stalk
- 10–50 mm
- Length of peduncle
- Up to 1000 mm
- Marks on petals
- there are no noticeable marks on the petals
- Nectar spur
- the flower has no nectar spurs
- Number of carpels
- 3
- Number of pistils
- 1
- Number of sepals and/or petals
- there are six petals, sepals or tepals in the flower
- Number of styles
- 1
- Ovary position
- the ovary is above the point of petal and/or sepal attachment
- Petal and sepal arrangement
- the flower includes two cycles of petal- or sepal-like structures
- Petal appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal base
- the petal narrows gradually or does not narrow at the base
- Petal fusion
- the perianth parts are separate
- Petal hairs on inner/upper surface
- there are no hairs on the inner/upper petal surface
- Sepal appearance
- the sepals resemble petals in color and texture
- Sepal length
- 3–4.5 mm
- Sepal orientation
-
- the sepals are pressed against the plant, or jutting stiffly upward
- the sepals are slightly curved outwards from the plant
- Sepals fused only to sepals
- the sepals are separate from one another
- Spathe
-
- the plant does not have a spathe
- the plant has a spathe surrounding the flower spike
- Spathe form
-
- NA
- the spathe just wraps around the base of the spike of flowers
- Stamen number
- 6
- Stamen position relative to petals
- NA
- Stamen types
- the stamens within a cycle are distinctly of two types
- Stamens fused
- the stamens are not fused to one another
- Stamens fused outwards
- the stamens are fused to the petals or tepals at or near their bases
- Style petal-like
- the style is not broad and flattened like a petal
- Tepals
- the petals and sepals are similar in size and color
-
Fruits or seeds
- Berry color
- NA
- Capsule ridges
- there are no ribs or wings on the capsule
- Fruit compartments
- there are three locules in the fruit
- Fruit cross-section
- the fruit is round in cross-section
- Fruit length
- Up to 5 mm
- Fruit stalk orientation
- the fruits point upward or spread or curve outward
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit type (specific)
- the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)
- Other markings on berry
- NA
-
Glands or sap
- Sap
- the sap is clear and watery
-
Growth form
- Lifespan
- the plant lives more than two years
- Root septa
- the roots do not have transverse septa
- Underground organs
- the plant has one or more swollen storage organs underground, such as bulbs, tubers or corms
-
Leaves
- Hairs on underside of leaf blade
- the underside of the leaf is not hairy, or has very few hairs
- Hairs on upper side of leaf blade
- the upper side of the leaf is not hairy, or has very few hairs
- Leaf arrangement
- basal: the leaves are growing only at the base of the plant
- Leaf blade basal lobes
- the leaf blades do not have basal lobes
- Leaf blade base
- the leaf has no stalk
- 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
- Leaf blade bloom
- the underside of the leaf blade has no noticeable waxy or powdery bloom
- Leaf blade cross-section
- the leaf blade is round or semicircular
- Leaf blade faces
- both surfaces of the leaf blade are exposed
- Leaf blade form
- Fully-formed (i.e., expanded), +/- green leaf blades are found somewhere on the plant
- Leaf blade length
- 100–500 mm
- Leaf blade orientation
- the upper surface of the leaf blade faces the stem of the plant
- Leaf blade shape
- the leaf blade is linear (very narrow with more or less parallel sides)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade tip
-
- the tip of the leaf blade is acuminate (tapers to a long, thin point)
- the tip of the leaf blade is acute (sharply pointed)
- Leaf blade veins
- the lateral veins are parallel or slightly arched in the direction of the tip
- Leaf blade width
- 3–20 mm
- Leaf stalk length
- 0 mm
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets
- Leaflet number
- 0
- Stipule twining
- NA
- Stipules
- there are no stipules on this plant
-
Place
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
-
- man-made or disturbed habitats
- meadows or fields
-
Scent
- Plant odor
- the leaves smell of onion or garlic
-
Stem, shoot, branch
- Flowering stem growth form
- the flowering stem is held upright
- Flowering stem interior
-
- the flowering stem is hollow
- the flowering stem is solid
- Flowering stem leaves
- there are no true leaves on the flowering stem
Wetland status
Not classified
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- absent
- 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)
var. cepa
- Massachusetts
- unranked (S-rank: SNR)
var. viviparum
- Massachusetts
- unranked (S-rank: SNR)
From Flora Novae Angliae dichotomous key
2. Allium cepa L. E
garden onion. Allium cepa L. var. bulbiferum Bailey; A. cepa L. var. viviparum M.C. Metz • CT, MA, ME, NH, VT. Fields and disturbed soil in areas of cultivation or agriculture. Many different cultivars exist for this plant. Some of them have bulbils in the inflorescence. Leaf blade characteristics will serve to identify such plants.