- You are here:
- Dichotomous Key
- Asteraceae
- Asteraceae Group 6
- Helianthus
- Helianthus debilis
Helianthus debilis — weak sunflower
Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.
Facts
Cucumber-leaved sunflower has been recorded throughout New England, but this is probably outside its native range of eastern and southeastern states. It inhabits fields, roadsides and waste areas.
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 (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 teeth
- Flower type in flower heads
-
- the flower head has disk flowers only, and lacks the strap-shaped flowers
- 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
- 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
- 25–140 mm
- Disk flower number
- 21-50
-
Flowers
- Bract cycle number
-
- there are three or more cycles of bracts
- there are two main cycles of bracts
- Bract margins
-
- there are few or no fine hairs along the bract margins
- there are fine hairs along the bract margins
- Bract outer side hair type
- the bracts are hairy, with simple hairs on their outer surface
- Bract outer side hairs
- the bracts are hairy on their outer surfaces
- Bract shape
- the main bracts are lanceolate (widest above the base, then taper narrowly towards the tip)
- Bract spines
- the bracts have no spines
- Bract tip orientation
- the bracts are pressed against the plant, or spreading out at the tips
- Bract tip shape
- the tips of the bracts are acuminate (tapered to a narrow point)
- Bracts
- the bracts in separate cycles are similar or gradually changing from the outer to inner cycles
- Disk flower color
-
- blue to purple
- pink to red
- Disk flower number
- 21-50
- Disk flower reproductive parts
- the disk flower has both pollen- and seed-producing parts
- Disk width
- 16–20 mm
- Flower head number
- each flowering stem has four or more 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 profile
- the disk is flat or nearly flat across the top
- Flower type in flower heads
-
- the flower head has disk flowers only, and lacks the strap-shaped flowers
- 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
- Inflorescence branching (Solidago)
- NA
- Inflorescence shape
- the inflorescence is not flat-topped but appears rounded, with some flower heads distinctly higher than others
- Ovary beak
- there is no beak on the ovary
- Ovary cross-section
- the ovary is compressed (flattened)
- Ovary hair type
- the ovary has hairs on it, but the hairs have no glands
- Ovary hairs
- the ovary has hairs on it
- Ovary profile
- in profile, the ovary is another shape
- 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
- 30–60 mm
- Reproductive system
- all the flowers on the plant contain both carpels and stamens
- Style branch number
- the style has two branches
- Style branches
- the style branch is wider at the tip and has a flattened end, or the style branches are wider at the tips and have flattened ends
- Width of flower head base
- 20–25 mm
-
Fruits or seeds
- Number of pappus parts
- 2
- Ovary length in developed fruit
- 2.5–3.2 mm
- Seed hair tuft bases
- NA
- Seed hair tuft color
- NA
- Seed hair tuft details
- NA
- Seed hair tuft length
- 1–5 mm
- Seed hair tuft tips
- NA
- Seed hairs uniform
- NA
- Seed tuft scale number
- 2–6
- Seed tuft type
-
- the pappus is made of flat scales that are not split or frayed at the tips
- the pappus is made of stiff, tapering bristles
- 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
- Leaf blade glands
-
- the leaf blades have glandular (translucent) dots or scales
- the leaf blades have no glandular (translucent) dots or scales
-
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
- the plant has no spines
- Underground organs
- there are only slender roots on the plant
-
Leaves
- 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
- 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
- the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)
- the base of the leaf is cordate (heart-shaped) or sagittate (arrow-shaped)
- Leaf blade edges
- the edge of the leaf blade has teeth
- Leaf blade hairs
- the leaf blade has simple hairs with no glands, and not tangled or wooly
- Leaf blade length
- 25–140 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)
- the leaf blade is triangular, with the stalk or attachment point on one of the sides
- Leaf blade tip
-
- the tip of the leaf blade is acuminate (tapers to a long, thin point)
- the tip of the leaf blade is acute (sharply pointed)
- Leaf blade veins
- the leaf blade has three main veins running from the base towards the tip
- Leaf blade width
- 15–90 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
- 30–60 mm
- Leaf type
- leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Specific leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets
-
Place
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- man-made or disturbed habitats
- meadows or fields
-
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 internode hair direction
- the hairs point mostly upwards to outwards
- Stem internode hairs
-
- the stem has hairs between the nodes
- the stem has no hairs between the nodes
Wetland status
Occurs only in non-wetlands. (Wetland indicator code: UPL)
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.
ssp. cucumerifolius
- Massachusetts
- not applicable (S-rank: SNA)
- Vermont
- not applicable (S-rank: SNA)
Subspecies and varieties
Our subspecies is Helianthus debilis Nutt. ssp. cucumerifolius.
From Flora Novae Angliae dichotomous key
2. Helianthus debilis Nutt. ssp. cucumerifolius (Torr. & Gray) Heiser E
weak sunflower. Helianthus cucumerifolius Torr. & Gray; H. debilis Nutt. var. cucumerifolius (Torr. & Gray) Gray • CT, MA, ME, NH, RI, VT. Roadsides, fields, waste areas.
Native to North America?
Yes and no (some introduced)
Sometimes confused with
- Helianthus petiolaris:
- chaff near the center of the disk conspicuously pubescent near the apex with long, white hairs, cypselas not mottled, pubescent with appressed-ascending hairs and leaf blades pale green and strigose (vs. H. debilis, with chaff near the center of the disk inconspicuously short-pubescent, cypselas mottled, pubescent with spreading-ascending hairs, and leaf blades dark green and scabrous).
Synonyms
- Helianthus cucumerifolius Torr. & Gray
- Helianthus debilis Nutt. var. cucumerifolius (Torr. & Gray) Gray