- You are here:
- Full Key
- All other flowering non-woody plants
- Daisies, goldenrods, and other aster family plants
- Gamochaeta pensylvanica
Gamochaeta pensylvanica — Pennsylvania cudweed
Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.
Facts
Pennsylvania cudweed, despite its name, is likely native to South America and has been introduced along the eastern seaboard as far north as Massachusetts. It is a plant of exposed moist soils and waste areas.
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
- 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 no teeth or lobes
- Flower type in flower heads
- the flower head has disk flowers only, and lacks the strap-shaped flowers
- Ray flower color
- NA
- Tuft or plume on fruit
- at least a part of the plume is made up of fine bristles
- Spines on plant
- the plant has no spines
- Leaf blade length
- 20–70 mm
- Disk flower number
- more than 50
-
Flowers
- Bract color
- the bracts are colored, or at least tinged with, pink, red or purple
- 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 curled, tangled, matted, or woolly hairs
- Bract outer side hairs
- the bracts are hairy on their outer surfaces
- Bract shape
-
- the main bracts are oblong (roughly rectangular but rounded at the ends)
- the main bracts are of a different shape than the given options
- the main bracts are ovate (egg-shaped)
- Bract spines
- the bracts have no spines
- Bract texture
- the bracts appear thin, flexible and nearly translucent
- Bract tip color
- the tips are a different color from the center of the bract
- Bract tip shape
-
- the tips of the bracts acute (have a sharp point)
- the tips of the bracts are acuminate (tapered to a narrow point)
- the tips of the bracts are obtuse (have a blunt point)
- Bracts
- there are at least two distinct forms of bracts in different cycles
- Disk flower color
-
- blue to purple
- yellow
- Disk flower number
- more than 50
- Disk flower reproductive parts
- the disk flower has both pollen- and seed-producing parts
- Disk flower shape
- the disk flower is tube-shaped (cylindrical), or gradually widening like a funnel
- Flower head outer flowers
- at the outer edge of the flower head, the flowers have no enlarged lobe or strap, and are of similar size as those in the center of the disk
- Flower head platform
- the base has no bristles or papery scales
- Flower head platform surface
- NA
- Flower head position
- some or all the flower heads are grouped in clusters of two or more
- Flower head profile
- the disk is flat or nearly flat across the top
- Flower head shape
- the flower head is cup-shaped (the sides diverge, then curve upwards and become parallel)
- Flower type in flower heads
- the flower head has disk flowers only, and lacks the strap-shaped flowers
- Height of flower head base
- 3–5 mm
- Inflorescence branching (Solidago)
- NA
- Inflorescence shape
- the inflorescence is not flat-topped but appears rounded, with some flower heads distinctly higher than others
- Inflorescence stem
- hairs are present on the stem of the inflorescence
- Ovary attachment
- the ovary is attached at or near the base
- 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 oblong (roughly rectangular but rounded at the ends)
- Ray flower color
- NA
- Ray flower reproductive parts
- NA
- Ray flowers
- NA
- Ray length
- 0 mm
- Reproductive system
- some of the flowers on the plant have only carpels or stamens, while others have both carpels and stamens
- Scale tip
- NA
- Smaller bracts at base of bracts
- there is a cycle of much smaller bracts outside the cycle of larger and longer bracts
- Style branch number
- the style has two branches
-
Fruits or seeds
- Number of pappus parts
- 11 or more
- Ovary length in developed fruit
- 0.4–0.9 mm
- Seed hair tuft bases
- the pappus hairs are attached to one another near the base
- Seed hair tuft details
- the pappus hairs are hooked or barbed
- Seed tuft type
- the pappus is made of very fine hairs or bristles
- Tuft or plume on fruit
- at least a part of the plume is made up of fine bristles
-
Glands or sap
- Ovary glands
- there are glands on the ovary surface
- Sap
- the sap is clear and watery
-
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
- the plant is biennial, it appears as either first year (non-reproductive) plants or second year plants with flowers or fruit
- Spines on plant
- the plant has no spines
- Underground organs
- there is a thickened taproot on the plant
-
Leaves
- Final leaf segment length (compound lvs only)
- 0 mm
- Final leaf segment width (compound lvs only)
- 0 mm
- Hairs on underside of leaf blade
- the underside of the leaf is fuzzy or hairy
- Hairs on upper side of leaf blade
- the upper side of the leaf is fuzzy or hairy
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade base
- the leaf has no 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 edges
- the edge of the leaf blade has no teeth or lobes
- Leaf blade flatness
- the leaf is flat (planar) at the edges
- Leaf blade hairs
- the leaf blade has tangled or woolly-looking hairs
- Leaf blade length
- 20–70 mm
- Leaf blade shape
-
- the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
- 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 tip
-
- the tip of the leaf blade is acute (sharply pointed)
- the tip of the leaf blade is obtuse (bluntly pointed)
- Leaf blade veins
- the leaf blade has one main vein running from the base towards the tip
- Leaf blade width
- 4–16 mm
- Leaf disposition
-
- the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- the lower leaves are larger, toothier, and/or on longer stalks than the upper leaves
- Leaf spines
- there are no spines on the leaf edges
- Leaf stalk
- the leaves have no leaf stalks, but attach directly to the stem
- Leaf stalk length
- 0 mm
- Leaf type
- leaves are simple (lobed or unlobed but not separated into leaflets)
- Leaflet number
- 0
- Specific leaf type
- the leaves are simple (lobed or unlobed but not separated into leaflets
- Teeth per side of leaf blade
- 0
-
Place
- Habitat
- terrestrial
- New England state
- Massachusetts
- Specific habitat
- man-made or disturbed habitats
-
Stem, shoot, branch
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Stem internode hair direction
- the hairs point mostly upwards to outwards
- Stem internode hair type
- at least some of the hairs on the stem are tangled, matted or woolly
- Stem internode hairs
- the stem has hairs between the nodes
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
1. Gamochaeta pensylvanica (Willd.) Cabrera E
Pennsylvania cudweed. Gnaphalium pensylvanicum Willd.; G. purpureum Willd. var. spathulatum (Lam.) Baker • MA. Dumps, disturbed soil.