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

Oenothera oakesiana — Oakes' evening-primrose

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Facts

Oakes' evening-primrose is native to northeastern North America, and has been introduced in other temperate regions. It can be found in all New England states, although it is most common on the coastal plain. Near the coast it inhabits dunes, upper beaches and open areas, and elsewhere it is most likely to be found in fields, roadsides and railroads.

Habitat

Anthropogenic (man-made or disturbed habitats), coastal beaches (sea beaches), dunes, meadows and fields

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
  • orange
  • pink to red
  • yellow
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 has teeth
  • 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 four petals, sepals, or tepals in the flower
Fusion of sepals and petals
both the petals and sepals are separate and not fused
Stamen number
8
Fruit type (general)
the fruit is dry and splits open when ripe
Fruit length
15–40 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
    3–7 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
    Anther tube length
    0 mm
    Calyx growth after flowering
    NA
    Calyx symmetry
    there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)
    Carpel hairs
    the carpels have hairs, but they are not thick and woolly
    Carpels fused
    the carpels are fused to one another
    Cilia on petals
    the petal margins do not have cilia
    Cleistogamous flowers
    there are no cleistogamous flowers on the plan
    Corolla morphology
    NA
    Corolla palate
    no
    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 appearance
    the flowers appear after the leaves have appeared
    Flower description
    the flower has an inferior ovary, with or without a hypanthium
    Flower orientation
    the flower bends downwards or hangs downwards
    Flower petal color
    • orange
    • pink to red
    • yellow
    Flower reproductive parts
    the flower has both pollen- and 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
    the petals are not fringed
    Fused stamen clusters
    NA
    Fusion of sepals and petals
    both the petals and sepals are separate and not fused
    Hairs on flower stalk
    NA
    Hairs on inflorescence
    • at least some of the hairs on the axis of the inflorescence have glands
    • the axis of the inflorescence has hairs entirely without glands
    Horns in hoods (Asclepias)
    NA
    Hypanthium
    the flower has a hypanthium
    Hypanthium length
    15–40 mm
    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
    Interior flower disk
    the flower does not have an interior disc
    Length of flower stalk
    0 mm
    Marks on petals
    there are no noticeable marks on the petals
    Nectar spur
    the flower has no nectar spurs
    Number of branches in umbel
    0
    Number of carpels
    4
    Number of pistils
    1
    Number of sepals, petals or tepals
    there are four petals, sepals, or tepals in the flower
    Number of styles
    1
    Ovary position
    the ovary is below the point of petal and/or sepal attachment
    Perianth shape
    • the perianth is campanulate (bell-shaped, with a tube about as long as wide, flaring at the mouth)
    • the perianth is cupuliform (cup-shaped)
    • the perianth is rotate (platter-shaped, the corolla flattened, circular, with nearly horizontally spreading lobes)
    Petal and sepal arrangement
    the flower includes two cycles of petal- or sepal-like structures
    Petal and sepal colors
    • orange
    • pink to red
    • yellow
    Petal appearance
    the petals are thin and delicate, and pigmented (colored other than green or brown)
    Petal base
    the petal narrows abruptly at the base
    Petal folds or pleats
    the petals of the flower do not have folds or plaits
    Petal glandular dots or scales
    no
    Petal hairs (Viola)
    NA
    Petal hairs on inner/upper surface
    there are no hairs on the inner/upper petal surface
    Petal length
    10–20 mm
    Petal length relative to sepals
    • the petals are about equal in length to the sepals
    • the petals are longer than the sepals
    Petal nectaries
    the petals do not have nectaries
    Petal number
    4
    Petal shape
    the petal outline is obovate (roughly egg-shaped, but with the widest point above the middle of the leaf blade)
    Petal tip shape
    the petal tip is retuse (with a blunt or rounded apex and a notch at the center)
    Petal tips (Cuscuta)
    NA
    Raceme attachment (Veronica)
    NA
    Reproductive system
    all the flowers have both carpels and stamens (synoecious)
    Scales inside corolla
    NA
    Sepal and petal color
    the sepals are different from the petals
    Sepal appearance
    the sepals are green or brown, and leaf-like in texture
    Sepal appendages
    the sepals have one or more appendages on them
    Sepal appendages (Oenothera)
    the appendages are attached part way down the sepals and separate in bud
    Sepal auricles
    there is one auricle per sepal
    Sepal cilia
    the sepals do not have cilia
    Sepal color
    • green to brown
    • yellow
    Sepal length
    9–17 mm
    Sepal number
    4
    Sepal orientation
    the sepals are curved outwards and downwards from the corolla
    Sepal relative length
    • the sepal lobes are approximately the same length as the fused portion
    • the sepal lobes are shorter than the fused portion
    Sepal shape
    • the sepal outline is lanceolate (lance-shaped; narrow, gradually tapering from the base to the tip)
    • the sepal outline is linear (extremely narrow, thread-like)
    Sepal tip shape
    the sepal tip is acute (is sharply pointed)
    Sepal uniformity
    all the sepals are about the same size
    Sepals fused only to sepals
    • the sepals are fused to each other (not other flower parts), at least near their bases
    • the sepals are separate from one another
    Spur length
    0 mm
    Spur number
    NA
    Stamen appendages
    stamen appendages are absent
    Stamen attachment
    • the stamens are attached at or near the bases of the petals or tepals
    • the stamens are attached at or near the bases of the petals or tepals
    Stamen lengths differ
    the stamens are all approximately the same length
    Stamen morphology
    the stamens within each cycle are the same
    Stamen number
    8
    Stamen position relative to petals
    NA
    Stamen relative length
    anything
    Stamens fused
    the stamens are not attached to one another
    Staminodes
    there are no staminodes on the flower
    Stigma length
    2.5–6 mm
    Stigma position
    the stigmas are positioned at the tip of the style
    Style length
    0–25 mm
    Style petal-like
    the styles are not petal-like
    Style relative length
    • the stigma does not protrude beyond the mouth of the corolla
    • the stigma protrudes beyond the mouth of the corolla
    Surface of ovary
    the ovary surface has no points, bumps or wrinkles
    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
    the capsule has four prominent ribs or wings
    Capsule splitting
    the capsule splits by four main valves, teeth or pores
    Fruit (pyxis) dehiscence
    NA
    Fruit beak length
    0 mm
    Fruit cross-section
    • the fruit is roughly quadrangular in cross-secgtion
    • the fruit is round in cross-section
    Fruit features (Brassicaceae)
    NA
    Fruit length
    15–40 mm
    Fruit length relative to sepals
    NA
    Fruit locules
    four
    Fruit shape
    the fruit is lanceoloid (narrow, widest below the middle and tapering at both ends)
    Fruit stalk orientation
    NA
    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)
    Hair type on fruit
    the hairs on the fruits are simple (not branched), don’t have glands, and are not woolly
    Hairs on fruit
    the fruits have hairs on them
    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
    Ovary stipe length
    0 mm
    Placenta arrangement
    • the plant has axile placentation, in which the ovules are attached where the septa of a compound ovary are united, usually on the central axis, or to the septa themselves
    • the plant has parietal placentation, where ovules develop on the wall or slight outgrowths of the wall forming broken partitions within a compound ovary
    Relative fruit length
    0
    Rows of seeds in fruit (Brassicaceae)
    NA
    Schizocarpic fruit compression
    NA
    Schizocarpic fruit segments
    0
    Seed length
    1.1–1.2 mm
    Seed relative length
    the seed is longer than it is wide
    Seed surface
    the seed has pits or depressions on it
    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 for two years
    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 number (Apiaceae)
    0
    Bracteoles
    the plant has bracteoles between the primary bracts and the flowers
    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 bracts
    the flower has one or more bracts associated with 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)
    • 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 base symmetry
    the leaf blade base is symmetrical
    Leaf blade bloom
    the underside of the leaf has no noticeable bloom
    Leaf blade edges
    • the edge of the leaf blade has teeth
    • 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
    35–300 mm
    Leaf blade primary vein pattern
    the secondary veins branch off at intervals from the primary vein
    Leaf blade shape
    • the leaf blade is elliptic (widest near the middle and tapering at both ends)
    • the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
    Leaf blade surface colors
    the upper side of the leaf blade is relatively uniform in color
    Leaf blade texture
    the leaf blade has a fleshy or spongy texture
    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
    5–30 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 hair orientation
    the hairs are flat against the leaf surface, mostly pointing towards the leaf tip
    Leaf sheath length
    0 mm
    Leaf shiny
    the upper side of the leaf is dull or slightly shiny
    Leaf spines
    there are no spines on the leaf edges
    Leaf stalk
    • the leaves have leaf stalks
    • the leaves have no leaf stalks, but attach directly to the stem
    Leaf stalk attachment to leaf
    • NA
    • the petiole attaches at the basal margin of the leaf blade
    Leaf stalk base
    • NA
    • the petiole base is narrow where it attaches to the stem
    Leaf stalk length
    At least 0 mm
    Leaf teeth and lobes
    • the edge of the leaf blade is entire (has no teeth or lobes)
    • the leaf blade margin has outward-pointing teeth
    Leaf tip
    the tip of the leaf blade is acute (sharply pointed)
    Leaf type
    the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
    Leaf types
    There is an abrupt 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 the basal leaves of conspicuously different shape or form than those slightly higher up.
    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

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • dunes
    • man-made or disturbed habitats
    • meadows or fields
    • sea beaches

  • Scent

    Plant odor
    the plant does not have much of a smell

  • Stem, shoot, branch

    Branched tendrils
    NA
    Direction of stem hairs
    • the hairs are pressed flat against the plant, pointing towards the plant's tip
    • 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
    10–60 cm
    Stem bloom
    there is no powdery or waxy film on the stem
    Stem hair distribution
    the hairs on the stem are distributed more of less uniformly
    Stem nodes swollen
    the stem is not swollen at the nodes
    Stem orientation
    • the stems are upright or angled outwards
    • the stems trail at the base, but may turn upwards at the tips
    Stem roughness between nodes
    the stem does not feel rough
    Stem spacing
    the plant is solitary, or a few plants are growing together
    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

Not classified

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
fairly widespread (S-rank: S4)

From Flora Novae Angliae dichotomous key

10.  Oenothera oakesiana (Gray) J.W. Robbins ex S. Wats. & Coult. N

Oakes’ evening-primrose. Oenothera angustissima R.R. Gates; O. biennis L. var. oakesiana Gray; O. cruciata Nutt. ex G. Don var. stenopetala (Bickn.) Fern.; O. parviflora L. ssp. angustissima (R.R. Gates) Munz; O. parviflora L. var. angustissima (R.R. Gates) Wieg.; 
 O. parviflora L. var. oakesiana (Gray) Fern. • CT, MA, ME, NH, RI, VT; most common on the 
coastal plain. Fields, roadsides, railroads, coastal dunes, upper beaches, and open areas.

Native to North America?

Yes

Sometimes confused with

Oenothera parviflora:
plants variously hairy with a mixture of blister-based hairs, glandular-hairs, and/or minute, appressed hairs (vs. O. oakesiana, with the plants densely and uniformly hairy with minute, appressed hairs.
Oenothera villosa:
sepal appendages borne at the true tip of the sepal, therefore, the true tip not projecting as a small scale below what appears to be the apex of the sepal (vs. O. oakesiana, with the sepal appendages borne just below the true tip of the sepal, therefore, the true tip appearing as a small, scale-like projection below what appears to be the apex of the sepal).

Synonyms

  • Oenothera angustissima R.R. Gates
  • Oenothera biennis L. var. oakesiana Gray
  • Oenothera cruciata Nutt. ex G. Don var. stenopetala (Bickn.) Fern.
  • Oenothera parviflora L. ssp. angustissima (R.R. Gates) Munz
  • Oenothera parviflora L. var. angustissima (R.R. Gates) Wieg.
  • Oenothera parviflora L. var. oakesiana (Gray) Fern.

Family

Onagraceae

Genus

Oenothera