Helianthus grosseserratus — saw-toothed sunflower
![Plant form: Helianthus grosseserratus. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com:443/taxon-images-1000s1000/Asteraceae/helianthus-grosseserratus-ha-ahaines.jpg)
![Leaves: Helianthus grosseserratus. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com:443/taxon-images-1000s1000/Asteraceae/helianthus-grosseserratus-le-ahaines.jpg)
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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.
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enlargeFacts
Saw-toothed sunflower is native to the midwestern United States, but has spread as a weed into the Southeast, Canada, and New England. It has been used to make folk remedies including a tea to reduce fevers and loosen phlem, and the stems were used to treat malaria and burns. It occasionally forms hybrids with other sunflower (Helianthus) species.
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields
Characteristics
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Leaf type
- 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
- opposite: there are two leaves per node along the stem
- Leaf blade edges
-
- 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 tubular disk flowers in the center and ray flowers, these often strap-shaped, around the periphery
- Ray flower color
- yellow
- Tuft or plume on fruit
- there is no plume, or the plume is made up of scales, awns, a crown, or a rim
- Spines on plant
- the plant has no spines
- Leaf blade length
- 100–320 mm
- Disk flower number
- more than 50
-
Flowers
- Bases of bract appendages
- NA
- Bract margins
- there are fine hairs along the bract margins
- Bract outer side hairs
-
- the bracts are hairy on their outer surfaces
- the bracts are not hairy on their outer surfaces
- Bract shape
-
- the main bracts are lanceolate (widest above the base, then taper narrowly towards the tip)
- the main bracts are linear (long and very narrow)
- Bract width
- 1.5–2.5
- Disk flower color
- yellow
- Disk flower lobe number
- 5
- Disk flower number
- more than 50
- Disk flower reproductive parts
- the disk flower has both pollen- and seed-producing parts
- Disk width
- 15–25 mm
- Flower head number
-
- each flowering stem has four or more flower heads on it
- each flowering stem has only one to three flower heads on it
- 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 papery scales on it
- Flower head shape
- the flower head is hemispherical (like the bottom half of a sphere)
- Flower type in flower heads
- the flower head has tubular disk flowers in the center and ray flowers, these often strap-shaped, around the periphery
- Inflorescence branching (Solidago)
- NA
- Number of bracts at flower head base
- 25–30
- 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
- Peduncle length
- 3–100 mm
- Ray flower color
- yellow
- Ray flower reproductive parts
- there are neither carpels nor stamens in the ray flowers
- Ray flowers
-
- 11-15
- 16-25
- Ray length
- 23–40 mm
- Width of flower head base
- 15–25 mm
-
Fruits or seeds
- Number of pappus parts
- 2
- Ovary beak length
- 3–4 mm
- Seed hair tuft bases
- NA
- Seed hair tuft color
- NA
- Seed hair tuft details
- NA
- Seed hair tuft length
- 1.9–2.5 mm
- Seed hair tuft tips
- NA
- Seed hairs uniform
- NA
- Seed tuft scale number
- 2
- Seed tuft type
- the pappus is made of flat scales that are not split or frayed at the tips
- Top of disk flower ovary
- NA
- Tuft or plume on fruit
- there is no plume, or the plume is made up of scales, awns, a crown, or a rim
-
Glands or sap
- Bract resin
- the bracts have no resin or resin glands
- Leaf blade glands
- the leaf blades have glandular (translucent) dots or scales
- 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 perennial, it shows evidence of previous year's leaves, stems or stem bases
- 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
- 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
- Leaf arrangement
-
- alternate: there is one leaf per node along the stem
- opposite: there are two leaves per node along the stem
- Leaf blade base
- the leaf has a distinct 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 bloom
- the underside of the leaf has no noticeable bloom
- Leaf blade edges
-
- the edge of the leaf blade has no teeth or lobes
- the edge of the leaf blade has teeth
- Leaf blade hairs
- the leaf blade has tangled or woolly-looking hairs
- Leaf blade length
- 100–320 mm
- Leaf blade shape
-
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Leaf blade surface colors
- there is no noticeable color variation on the upper surface of the leaf
- Leaf blade tip
- the tip of the leaf blade is acuminate (tapers to a long, thin point)
- Leaf blade veins
- the leaf blade has three main veins running from the base towards the tip
- Leaf blade width
- 12–90 mm
- Leaf disposition
- the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- Leaf spines
- there are no spines on the leaf edges
- Leaf stalk
- the leaves have leaf stalks
- Leaf stalk length
- 1–5 mm
- Leaf tip extension
- NA
- Leaf type
- leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaflet number
- 0
- Specific leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets
- Teeth per side of leaf blade
- At least 0
-
Place
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- 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
- Stem internode hair direction
- the hairs are pressed flat against the plant, pointing either towards the plant's tip or towards it's base
- Stem internode hair length
- At least 0 mm
- Stem internode hair type
- the stem has no hairs between the nodes
- Stem internode hairs
- the stem has no hairs between the nodes
- Stem wings
- the stem does not have wings on it
Wetland status
Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)
New England distribution and conservation status
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- absent
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- not applicable (S-rank: SNA)
Native to North America?
Yes and no (some introduced)
Sometimes confused with
- Helianthus giganteus:
- lobes of the disk corollas pubescent, anther appendages red-brown to dark brown, and leaf blades strongly scabrous on the adaxial surface (vs. H. grosseserratus, with lobes of the disk corollas glabrous or glabrate, anther appendages yellow, and leaf blades slightly, if at all, scabrous on the adaxial surface).
Synonyms
- Helianthus grosseserratus var. hypoleucus Gray
Family
Genus
From the dichotomous key of Flora Novae Angliae
6. Helianthus grosseserratus Martens E
saw-toothed sunflower. Helianthus grosseserratus Martens var. hypoleucus Gray • CT, MA, ME, NH, VT. Roadsides, fields, disturbed soil.
4×6. Helianthus divaricatus × Helianthus grosseserratus → Helianthus ×divariserratus R.W. Long is an extremely rare sunflower hybrid in New England known from CT. It has a glabrous and glaucous stem bearing opposite leaves that are triple-veined (those of H. grosseserratus are pinnately veined), rounded at the base, and borne on short petioles 5–10 mm long (those of H. divaricatus truncate to broadly rounded at the base and sessile). The involucral bracts are 10–15 mm long (6–12 mm long in H. divaricatus, 10–14 mm long in H. grosseserratus).
5×6. Helianthus giganteus × Helianthus grosseserratus → Helianthus ×luxurians E.E. Wats. is a very rare hybrid sunflower known from CT, MA. It closely resembles its parental species. It shows ± glabrous and glaucous stems, and variably toothed leaf blades (subentire to coarsely toothed) that are usually 5–10 times as long as wide and borne on short petioles 5–10 mm long.
6×8. Helianthus grosseserratus × Helianthus maximiliani → Helianthus ×intermedius R.W. Long is a very rare sunflower hybrid known from MA, ME. It has sparsely strigose stems, petioles 5–15 mm long, and flat leaf blades that are strongly scabrous adaxially.
6×H. salicifolius A. Dietr. Helianthus ×kellermanii Britt. is a rare and local hybrid known from MA, ME. It is similar to H. grosseserratus, differing primarily in the linear to narrow-lanceolate principal leaf blades that are 10–20 mm wide and taper to the petiole and lobes of the disk corollas that are white-pubescent on the abaxial surface (vs. principal leaf blades lanceolate to narrow-ovate, 12–90 mm wide, tapering or rounded to the petiole, and disk corolla lobes glabrous or nearly so).