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- Linnaea borealis
Linnaea borealis — American twinflower
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Facts
Research has shown that American twinflower cannot pollinate close relatives, and needs less closely-related individuals nearby in order to successfully set seed. Thus, if a population becomes small or isolated from others, it is more likely to die out.
Habitat
Alpine or subalpine zones, forests, talus and rocky slopes, woodlands
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
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Flower petal color
-
- pink to red
- white
- Leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf arrangement
- opposite: there are two leaves per node along the stem
- Leaf blade edges
- the edge of the leaf blade has teeth
- 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
- the petals or the sepals are fused into a cup or tube
- Stamen number
- 4
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit length
- 3 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 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 palate
- no
- Corona lobe length
- 0 mm
- Epicalyx
- the flower does not have an epicalyx
- Epicalyx number of parts
- 0
- Flower description
- the flower has an inferior ovary, with or without a hypanthium
- Flower length
- 10–15 mm
- Flower number
- 2
- Flower orientation
- the flower bends downwards or hangs downwards
- Flower petal color
-
- pink to red
- white
- 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 knob-like at the tip, and unbranched
- Fusion of sepals and petals
- the petals or the sepals are fused into a cup or tube
- Hairs on flower stalk
- the flower stalk has hairs on it
- Hairs on inflorescence
- at least some of the hairs on the axis of the inflorescence have glands
- 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
- Length of flower stalk
- 10–20 mm
- Length of peduncle
- 45–80 mm
- Marks on petals
- the petals have spots or streaks on them
- Nectar spur
- the flower has no nectar spurs
- Number of branches in umbel
- 0
- Number of sepals, petals or tepals
- there are five 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)
- Petal and sepal arrangement
- the flower includes two cycles of petal- or sepal-like structures
- Petal and sepal colors
-
- pink to red
- white
- Petal appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal folds or pleats
- the petals of the flower do not have folds or plaits
- Petal hairs (Viola)
- NA
- Petal hairs on inner/upper surface
- there are hairs on the inner/upper petal surface
- Petal length
- 10–15 mm
- Petal number
- 5
- Petal tips (Cuscuta)
- NA
- Raceme attachment (Veronica)
- NA
- Reproductive system
- all the flowers have both carpels and stamens (synoecious)
- Scales inside corolla
- no
- 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 do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Sepal color
- pink to red
- Sepal number
- 5
- Sepal shape
- the sepal outline is lanceolate (lance-shaped; narrow, gradually tapering from the base to the tip)
- Sepal uniformity
- all the sepals are about the same size
- Stamen morphology
- the stamens within a cycle differ in length or width
- Stamen number
- 4
- Stamen relative length
- anything
- Staminodes
- there are no staminodes on the flower
- Style petal-like
- the styles are not petal-like
- Style relative length
- the stigma protrudes beyond the mouth of the corolla
- 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
- Berry color
- NA
- Capsule color (Viola)
- NA
- Capsule splitting
- the capsule splits by three main valves, teeth or pores
- Carpel beak length
- 0 mm
- Fruit (pyxis) dehiscence
- NA
- Fruit beak length
- 0 mm
- Fruit features (Brassicaceae)
- NA
- Fruit length
- 3 mm
- Fruit locules
- three
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit type (specific)
- the fruit is a nut (dry and indehiscent, with a hard wall, usually containing only one seed and usually subtended by an involucre)
- Hair type on fruit
- the hairs on the fruits have glands at their tips
- 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
- 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
- Rows of seeds in fruit (Brassicaceae)
- NA
- Schizocarpic fruit compression
- NA
- Schizocarpic fruit segments
- 0
- Seed number
- 1
- 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 a subshrub (small shrub with partially herbaceous stems)
- the plant is an herb (it has self-supporting stems)
- Horizontal rooting stem
-
- the plant does not have stolons
- the plant has stolons
- Lifespan
- the plant lives more than 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
-
Leaves
- Bracteole length
- 1 mm
- Bracteole number (Apiaceae)
- 0
- Bracteole shape
- the bracteoles are lanceolate (widest below the middle, and tapering at both ends)
- 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 bract texture
- the floral bracts are green, with a leaf-like texture
- Floral bracts
- the flower has one or more bracts associated with it
- Flower bract length
- 1.5–2 mm
- Hooked hairs on underside of leaf
- no
- Inflated hairs on leaf
- the leaf blade does not have inflated hairs on it
- Leaf arrangement
- opposite: there are two leaves 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
- 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
- Leaf blade flatness
- the leaf is flat (planar) at the edges
- Leaf blade length
- 5–16 mm
- Leaf blade primary vein pattern
- the secondary veins branch off at intervals from the primary vein
- Leaf blade shape
-
- the leaf blade is orbicular (roughly circular, as wide as long)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade texture
- the leaf blade is coriaceous (has a firm, leathery 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
- 4–10 mm
- Leaf duration
- the leaves remain green all winter
- Leaf form
- the leaves are green, with an expanded blade and a leaf-like texture
- 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
- Leaf stalk attachment to leaf
- the petiole attaches at the basal margin of the leaf blade
- Leaf stalk length
- 2–3 mm
- Leaf teeth and lobes
-
- the leaf blade margin has outward-pointing teeth
- the leaf blade margin has rounded teeth
- Leaf tip
- 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
- NA
- 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 are two leaves 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
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- alpine or subalpine zones
- forests
- talus or rocky slopes
- woodlands
-
Scent
- Plant odor
- the plant does not have much of a smell
-
Stem, shoot, branch
- Branched tendrils
- NA
- Flowering stem cross-section
- the flowering stem is circular, or with lots of small angles so that it is roughly circular
- 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 bloom
- there is no powdery or waxy film on the stem
- Stem nodes swollen
- the stem is not swollen at the nodes
- Stem orientation
- the stems trail at the base, but may turn upwards at the tips
- 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
Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)
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.
- Connecticut
- unranked (S-rank: SNR)
- Maine
- unranked (S-rank: SNR)
ssp. americana
- Connecticut
- extremely rare (S-rank: S1), endangered (code: E)
- Massachusetts
- uncommon (S-rank: S3)
- Rhode Island
- historical (S-rank: SH), state historical (code: SH)
ssp. longiflora
- Maine
- sir (S-rank: sir)
Subspecies and varieties
Our subspecies is Linnaea borealis L. ssp. americana (Forbes) Hultén ex Clausen.
From Flora Novae Angliae dichotomous key
1. Linnaea borealis L. ssp. americana (Forbes) Hultén ex Clausen N
American twinflower. Linnaea americana Forbes; L. borealis L. var. americana (Forbes) Rehd. • CT, MA, ME, NH, RI, VT; becoming rare in southern New England. Mesic to wet-mesic, evergreen and mixed evergreen-deciduous forests, ascending to boreal situations.
Native to North America?
Yes
Synonyms
- Linnaea americana Forbes
- Linnaea borealis var. americana (Forbes) Rehd.