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 - Sonchus oleraceus
 
Sonchus oleraceus — common sow-thistle
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Facts
Common sow-thistle is native to Europe and introduced worldwide, including across North America. Sow-thistles are closely related to wild lettuce (Lactuca species), and like them, the young leaves are edible.
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
 - Rhode Island
 - Vermont
 
 
- Leaf type
 - leaves are simple (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 lobes, or it has both teeth and lobes
 - the edge of the leaf blade has no teeth or lobes
 - the edge of the leaf blade has teeth
 
 
- Flower type in flower heads
 - the flower head has ray flowers only, meaning all of the individual flowers of the flower head have a strap-shaped ray, which may or may not have teeth at the very tip of the ray
 
- Ray flower color
 - 
                                
                                    
- orange
 - yellow
 
 
- Tuft or plume on fruit
 - at least a part of the plume is made up of fine bristles
 
- Spines on plant
 - there are spines on the plant
 
- Leaf blade length
 - 60–350 mm
 
- Disk flower number
 - 0
 
- 
                        
Flowers
- Bases of bract appendages
 - NA
 
- Bract cycle number
 - there are three or more cycles of bracts
 
- Bract outer side hair type
 - 
                                
                                    
- the bracts are hairy on their outer surfaces, with hairs having glands (a swelling at the tip of the hair)
 - the bracts are hairy, with simple hairs on their outer surface
 - the bracts are not hairy on their outer surface
 
 
- Bract outer side hairs
 - 
                                
                                    
- the bracts are hairy on their outer surfaces
 - the bracts are not hairy on their outer surfaces
 
 
- Bract tip shape
 - the tips of the bracts acute (have a sharp point)
 
- Bracts
 - there are at least two distinct forms of bracts in different cycles
 
- Disk flower color
 - NA
 
- Disk flower lobe number
 - 0
 
- Disk flower number
 - 0
 
- Disk flower proportions
 - NA
 
- Disk flower reproductive parts
 - NA
 
- Disk flower shape
 - NA
 
- Flower head outer flowers
 - at the outer edge of the flower head, each flower has a single enlarged lobe or strap
 
- Flower head platform
 - the base has no bristles or papery scales
 
- Flower head platform surface
 - NA
 
- Flower type in flower heads
 - the flower head has ray flowers only, meaning all of the individual flowers of the flower head have a strap-shaped ray, which may or may not have teeth at the very tip of the ray
 
- Height of flower head base
 - 9–13 mm
 
- Inflorescence branching (Solidago)
 - NA
 
- Inflorescence shape
 - the inflorescence is flat-topped in profile
 
- Ovary beak
 - there is no beak on the ovary
 
- Ovary cross-section
 - the ovary is compressed (flattened)
 
- Ovary hair type
 - the ovary has no hairs on it
 
- Ovary hairs
 - the ovary has no hairs on it
 
- Ovary profile
 - in profile, the ovary is lance-shaped, but widest above the middle
 
- Ovary surface
 - the ovary surface is textured with tiny points, bumps or wrinkles
 
- Peduncle hair type
 - the hairs on the peduncles have glands at their tips
 
- Peduncle hairs
 - 
                                
                                    
- the peduncles are hairy
 - the peduncles have no hairs
 
 
- Ray flower color
 - 
                                
                                    
- orange
 - yellow
 
 
- Ray flower reproductive parts
 - the ray flowers have both carpels and stamens
 
- Ray flowers
 - more than 50
 
- Reproductive system
 - all the flowers on the plant contain both carpels and stamens
 
- Rim at top of ovary
 - the central flowers have no disk-shaped platform above the ovary
 
- Scale tip
 - NA
 
- Smaller bracts at base of bracts
 - there is no smaller, outer cycle of bracts
 
- Style branch number
 - there are no obvious branches on the style
 
- Swelling at base of flower head
 - the peduncles are not swollen, or only slightly
 
- Width of flower head base
 - 6–14 mm
 
 - 
                        
Fruits or seeds
- Ovary beak length
 - 0 mm
 
- Ovary length in developed fruit
 - 2.5–3.5 mm
 
- Seed hair tuft color
 - the pappus hairs are white or off-white
 
- Seed hair tuft details
 - the pappus hairs are hooked or barbed
 
- Seed hair tuft length
 - 5–8 mm
 
- Seed hair tuft tips
 - the pappus hairs are slender
 
- Seed hairs uniform
 - there are two distinct lengths of pappus hairs
 
- Seed tuft scale number
 - 0
 
- Seed tuft type
 - the pappus is made of very fine hairs or bristles
 
- Top of disk flower ovary
 - NA
 
- Tuft or plume on fruit
 - at least a part of the plume is made up of fine bristles
 
 - 
                        
Glands or sap
- Leaf blade glands
 - the leaf blades have no glandular (translucent) dots or scales
 
- Sap
 - the sap is milky and opaque, and may be white or colored
 
 - 
                        
Growth form
- Growth form
 - the plant has one or more free-standing stems
 
- Plant lifespan
 - the plant is annual, it lacks evidence of previous years' growth
 
- Spines on plant
 - there are spines on the plant
 
- Underground organs
 - there is a thickened taproot on the plant
 
 - 
                        
Leaves
- Hairs on underside of leaf blade
 - the underside of the leaf is not hairy, or has very few hairs
 
- Leaf arrangement
 - alternate: there is one leaf per node along the stem
 
- Leaf blade base
 - 
                                
                                    
- the leaf has no petiole
 - the leaf has no petiole and at the base it clasps the stem, or goes all the way around the stem so the stem appears to pierce the leaf
 
 
- Leaf blade base shape
 - the base of the leaf is cordate (heart-shaped) or sagittate (arrow-shaped)
 
- Leaf blade bloom
 - there is a noticeable powdery or waxy bloom on the underside of the leaf
 
- Leaf blade edges
 - 
                                
                                    
- the edge of the leaf blade has lobes, or it has both teeth and lobes
 - the edge of the leaf blade has no teeth or lobes
 - the edge of the leaf blade has teeth
 
 
- Leaf blade length
 - 60–350 mm
 
- 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 obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
 - the leaf blade is spatulate (spoon-shaped; narrow near the base, then suddenly widening to a rounded tip)
 
 
- Leaf blade surface colors
 - there is no noticeable color variation on the upper surface of the leaf
 
- Leaf blade width
 - 10–150 mm
 
- Leaf disposition
 - the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
 
- Leaf spines
 - there are spines along the leaf edges
 
- Leaf stalk
 - the leaves have no leaf stalks, but attach directly to the stem
 
- Leaf stalk length
 - 0 mm
 
- Leaf tip extension
 - NA
 
- Leaf type
 - leaves are simple (lobed or unlobed but not separated into leaflets)
 
- Leaflet number
 - 0
 
- Specific leaf type
 - the leaf has a row of two or more lobes on each side of the central axis
 
 - 
                        
Place
- Habitat
 - terrestrial
 
- New England state
 - 
                                
                                    
- Connecticut
 - Maine
 - Massachusetts
 - New Hampshire
 - Rhode Island
 - Vermont
 
 
- Specific habitat
 - 
                                
                                    
- man-made or disturbed habitats
 - meadows or fields
 
 
 - 
                        
Scent
- Plant odor
 - the plant does not have much of an odor
 
 - 
                        
Stem, shoot, branch
- Flowering stem cross-section
 - the flowering stem is circular, or with lots of small angles
 
- Leaves on stem
 - there is at least one full leaf above the base of the flowering stem
 
- Stem bloom
 - 
                                
                                    
- the stem has a powdery or waxy film on it that can be rubbed away
 - there is no powdery or waxy film on the stem
 
 
- Stem internode hair direction
 - NA
 
- Stem internode hair length
 - 0 mm
 
- Stem internode hair type
 - the stem has no hairs between the nodes
 
- Stem internode hairs
 - 
                                
                                    
- the stem has hairs between the nodes
 - the stem has no hairs between the nodes
 
 
- Stem wings
 - the stem does not have wings on it
 
 
Wetland status
Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)
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
 - unranked (S-rank: SNR)
 
From Flora Novae Angliae dichotomous key
3. Sonchus oleraceus L. E
common sow-thistle. CT, MA, ME, NH, RI, VT. Fields, roadsides, pastures, waste areas.
Native to North America?
No
Sometimes confused with
- Sonchus arvensis:
 - flower heads 3-5 cm wide and plants perennial from a deep-seated rhizome (vs. S. oleraceus, with flower heads 1.5-2.5 cm wide and plants annual from a taproot). Sonchus asper: basal auricles of leaves rounded and stalks to flower heads with abundant stipitate glands (vs. basal auricles of leaves +/- triangular and stalks to flower heads without stipitate glands or these few and sparse).