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- Dichotomous Key
- Violaceae
- Viola
- Viola key for chasmogamous flowering material
- Viola japonica
Viola japonica — Japanese violet
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Facts
N/A
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.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- terrestrial
- New England state
- Massachusetts
- Flower petal color
- blue to purple
- Leaf type
- the leaves are simple (lobed or unlobed but not separated into leaflets)
- Leaf arrangement
- the leaves are growing only at the base of the plant (basal)
- Leaf blade edges
- the edge of the leaf blade has teeth
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally 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
- 5
- Stem nodes swollen
- NA
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit length
- Up to 10 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 attachment
- the anther is attached by its base to the filament
 - Anther opening
- the anthers have narrow slits or furrows that run lengthwise along the anthers
 - Anther spurs
- there are spurs on the anthers
 - Anther tube length
- 0 mm
 - Calyx growth after flowering
- the calyx does not grow to cover or partially cover the fruit
 - Calyx symmetry
- there is only one way to evenly divide the calyx (the calyx is bilaterally symmetrical)
 - Carpels fused
- the carpels are fused to one another
 - Cilia on petals
- the petal margins do not have cilia
 - Cleistogamous flowers
- 
                                
                                    - the plant has some cleistogamous flower
- 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
 - Flower appearance
- 
                                
                                    - the flowers appear after the leaves have appeared
- the flowers appear at the same time as the leaves
 
 - Flower description
- the flower has a superior ovary, and lacks a hypanthium
 - Flower number
- 1
 - Flower orientation
- the flower bends downwards or hangs downwards
 - Flower petal color
- blue to purple
 - Flower reproductive parts
- the flower has both pollen- and seed-producing parts
 - Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
 - Flowers sunken into stem
- no
 - Form of style
- the style is knob-like 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
- 
                                
                                    - the flower stalk has hairs on it
- the flower stalk has no hairs on it
 
 - Horns in hoods (Asclepias)
- NA
 - Hypanthium
- the flower does not have a hypanthium
 - Hypanthium length
- 0 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
 - Marks on petals
- there are no noticeable marks on the petals
 - Nectar spur
- the flower has one or more nectar spurs
 - Number of branches in umbel
- 0
 - Number of carpels
- 3
 - Number of pistils
- 1
 - 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 above the point of petal and/or sepal attachment
 - Perianth shape
- NA
 - Petal and sepal arrangement
- the flower includes two cycles of petal- or sepal-like structures
 - Petal and sepal colors
- blue to purple
 - 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
- the petal narrows gradually or does not narrow at the base
 
 - Petal folding in bud
- the petals in bud are arranged in a cycle with edges overlapping like roof shingles (imbricate)
 - Petal folds or pleats
- the petals of the flower do not have folds or plaits
 - Petal glandular dots or scales
- no
 - Petal hairs (Viola)
- 
                                
                                    - the side petals of the flower are hairless
- the spurred petal of the flower is hairless
 
 - Petal hairs on inner/upper surface
- there are no hairs on the inner/upper petal surface
 - Petal length
- 11–15 mm
 - Petal length relative to sepals
- the petals are longer than the sepals
 - Petal nectaries
- the petals do not have nectaries
 - Petal number
- 5
 - Petal shape
- 
                                
                                    - the petal outline is oblong (rectangular, but with rounded ends)
- 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
- 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 auricles
- there is one auricle per sepal
 - Sepal cilia
- the sepals do not have cilia
 - Sepal color
- green to brown
 - Sepal features
- NA
 - Sepal length
- 5–7 mm
 - Sepal number
- 5
 - Sepal orientation
- the sepals are pressed against the corolla, or jutting stiffly upward
 - Sepal relative length
- NA
 - Sepal shape
- the sepal outline is lanceolate (lance-shaped; narrow, gradually tapering from the base to the tip)
 - Sepal texture
- the sepals are either very thin but flexible, like a membrane, or they are leaf-like in texture
 - Sepal tip shape
- the sepal tip is acuminate (tapers to a very narrow point)
 - Sepal uniformity
- all the sepals are about the same size
 - Sepals fused only to sepals
- the sepals are separate from one another
 - Spur length
- 5–10 mm
 - Spur number
- 1
 - Stamen appendages
- stamen appendages are present
 - Stamen attachment
- 
                                
                                    - the stamens are not attached to the petals or tepals
- the stamens are not attached to the petals or tepals
 
 - Stamen morphology
- the stamens within each cycle are the same
 - Stamen number
- 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 position
- the stigmas are positioned at the tip of the style
 - Style petal-like
- the styles are not petal-like
 - Style relative length
- the stigma does not protrude 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 ribs
- the capsule has no prominent ribs or wings
 - Capsule splitting
- the capsule splits by three main valves, teeth or pores
 - Fruit (pyxis) dehiscence
- NA
 - Fruit beak length
- 0 mm
 - Fruit cross-section
- the fruit is round in cross-section
 - Fruit features (Brassicaceae)
- NA
 - Fruit length
- Up to 10 mm
 - Fruit length relative to sepals
- the fruit is longer than its associated sepals
 - Fruit locules
- three
 - 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
- 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
 - Ovary stipe length
- 0 mm
 - Placenta arrangement
- the plant has parietal placentation, where ovules develop on the wall or slight outgrowths of the wall forming broken partitions within a compound ovary
 - Rows of seeds in fruit (Brassicaceae)
- NA
 - Schizocarpic fruit compression
- NA
 - Schizocarpic fruit segments
- 0
 - Seed relative length
- the seed is longer than 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 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
 - Underground organs
- the plant has a rhizome (a horizontal underground stem with roots growing from it)
 
- 
                        Leaves- Bracteole number (Apiaceae)
- 0
 - Bracteole shape
- 
                                
                                    - the bracteoles are lanceolate (widest below the middle, and tapering at both ends)
- the bracteoles are linear (very narrow, with more or less parallel sides)
 
 - 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 leaf stalk
- the petiole has no hairs on it
 - Hairs on underside of leaf
- 
                                
                                    - the underside of the leaf is fuzzy or hairy
- the underside of the leaf is not hairy, or it has very few hairs
 
 - Hairs on upper side of leaf
- 
                                
                                    - the upper side of the leaf is fuzzy or hairy
- the upper side of the leaf is not hairy, or it has very few hairs
 
 - Hooked hairs on underside of leaf
- no
 - Inflated hairs on leaf
- the leaf blade does not have inflated hairs on it
 - Leaf arrangement
- the leaves are growing only at the base of the plant (basal)
 - Leaf blade base
- the leaf has a distinct leaf stalk (petiole)
 - Leaf blade base shape
- 
                                
                                    - the base of the leaf blade is cordate (heart-shaped, has rounded lobes at the base)
- 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 hairs
- the leaf blade has simple hairs with no glands, and not tangled or wooly
 - Leaf blade length
- 30–80 mm
 - Leaf blade primary vein pattern
- the secondary veins branch off at intervals from the primary vein
 - Leaf blade shape
- 
                                
                                    - the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the leaf blade is oblong (rectangular but with rounded ends)
- 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 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
- 30–55 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 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 teeth and lobes
- the leaf blade margin has rounded teeth
 - Leaf tip
- 
                                
                                    - the tip of the leaf blade is acute (sharply pointed)
- the tip of the leaf blade is obtuse (bluntly pointed)
 
 - Leaf tufts in axils
- 
                                
                                    - NA
- there are no clusters of smaller leaves growing out of axils
 
 - Leaf type
- the leaves are simple (lobed or unlobed but not separated into leaflets)
 - Leaf types
- NA
 - Leaf variation
- NA
 - Leaflet number
- 0
 - Leaflet petiolules
- NA
 - Leaves per node
- the leaves are growing only at the base of the plant (basal)
 - Pinnately compound leaf type
- NA
 - Specific leaf type
- the leaves are simple (lobed or unlobed but not separated into leaflets)
 - Stipels
- NA
 - Stipule edges
- the stipule margins have teeth on them
 - Stipule features
- NA
 - Stipule fused to leaf stalk
- the stipules are fused to the petioles for some or most of their length
 - Stipule length
- 20–30 mm
 - Stipule shape
- the stipules are ovate (widest below the middle and broadly tapering at both ends)
 - Stipules
- the plant has stipules
 
- 
                        Place- Habitat
- terrestrial
 - New England state
- Massachusetts
 - Specific habitat
- man-made or disturbed habitats
 
- 
                        Scent- Plant odor
- the plant does not have much of a smell
 
- 
                        Stem, shoot, branch- Branched tendrils
- NA
 - Direction of stem hairs
- NA
 - Flowering stem cross-section
- NA
 - Hair between stem nodes
- NA
 - Hairs between stem nodes
- NA
 - Hooked hairs on stem between nodes
- NA
 - Leaves on stem
- the flowering stem has no leaves above the base
 - Length of hairs between stem nodes
- 0 mm
 - Plant height
- 2–45 cm
 - Stem bloom
- NA
 - Stem hair distribution
- NA
 - Stem nodes swollen
- NA
 - Stem orientation
- NA
 - Stem roughness between nodes
- NA
 - Stem spacing
- NA
 - Stem succulence
- NA
 - Tendril origin
- NA
 - Tendrils
- the plant does not have tendrils
 - Wings on stem
- NA
 
Wetland status
Not classified
In New England
Distribution
- Connecticut
- absent
- Maine
- absent
- Massachusetts
- present
- New Hampshire
- absent
- Rhode Island
- absent
- Vermont
- absent
Conservation status
None
From Flora Novae Angliae dichotomous key
9. Viola japonica Langsd. ex Ging. E
Japanese violet. MA. Gardens, waste areas. This species is responsible for reports of Viola chinensis G. Don in New England (i.e., the voucher specimens were misidentified).
![Plant form: Viola japonica. ~ By William and Linda Steere and the C.V. Starr Virtual Herbarium. ~ Copyright © 2025 William and Linda Steere and the C.V. Starr Virtual Herbarium. ~ Barbara Thiers, Director; bthiers[at]nybg.org ~ C.V. Starr Herbarium - NY Botanical Gardens](https://newfs.s3.amazonaws.com/taxon-images-239x239/Violaceae/viola-japonica-ha-cvstarr1.jpg) 
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