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Common Florida Roadside Sunflowers
Stephen H. Brown, Lee County Horticulture Agent
Kitty Tyler, Lee County Master Gardener
Introduction
Helianthus is Latin for sun (helios) flower (anthos). There are over 30 species of Helianthus common to North America. There are 14 distinct species in Florida, plus two known subspecies and
one recognized hybrid. Except for H. radula, these are North American sunflowers with yellow or
orange/reddish flowers and can be mistaken for flowers of the aster family also common in Florida. Sunflower species can be distinguished by differences in stems, leaves, flowers, and achenes
(fruits). Plant appearance in the landscape can differ than what is seen in the wild. This monograph
deals with a handful of sunflowers native to Florida.
Sunflowers produce composite compound flowers. Each flower is actually comprised of two types
of flowers. The showy ray florets, commonly known as petals, surround the disk florets in the center. The disk florets are the fertile florets and produce the seeds. Behind the ray florets are green
bracts (also known as phyllaries) and are arranged in a circle. Flower rays emerge slightly cupped
spreading and separating with age. Landscape plants usually flower earlier than plants in the wild.
Ray florets
Ray florets
Disk florets
Bracts
Bracts
Contents
H. agrestis (Southeastern Sunflower)
H. angustifolius (Narrowleaf Sunflower)
H. debilis (Beach Sunflower)
H. debilis subsp. cucumerifolius (Cucumberleaf Dune Sunflower)
H. radula (Rayless sunflower)
H. simulans (Muck Sunflower)
H. strumosus (Paleleaf Sunflower)
Typical Leaf Shapes
References
Links
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Southeastern Sunflower
Scientific Name: Helianthus agrestis
Range: Florida, South Georgia
Life Cycle: Annual
Reproduction: Seeds; rhizomes
Height: 4 to 9 feet tall
Common Use: Mass planting; pollinator plant
Additional Notes: Southeastern sunflower is a
branched, herbaceous annual which grows to 9
feet tall. This Helianthus can entirely cover open
marshes and is common following a fire. It can
make a good mass planting in an area where being visually attractive all years is not necessary.
This is perhaps the most commonly encounterd
wild sunflower in Southwest Florida.
State Road 78, near Banana Grove Road, Glades County. Mid October
State Road 78, near Banana Grove Road, Glades County. Mid October
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Southeastern Sunflower (Helianthus agrestis)
Stem: Tall and slender, about 0.50 inches diameter at its base and 0.13 inches at the top where
flowering begins. Smooth or with few hairs. Usually no functioning leaves at the base when flowering.
Leaf Type: Mostly opposite, sometimes alternate. Lance-elliptic shaped, entire or irregularly
toothed, with mostly rough upper surface. Three to six inches long and mostly 1.0-2.0 inches wide,
tapering to a short petiole that is often conspicuously rough or hairy. Petioles 0.3-0.6 inches long.
Petioles with hairs extending to the leaf blades
Basal stem
Opposite leaf arrangement
Irregularly toothed leaf blade
Alternate leaf arrangement
Leaf size comparisons. Larger
leaf is from the lower stem
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Southeastern Sunflower (Helianthus agrestis)
Inflorescence: Usually 2.5-3.25 inches across. Disks generally dark purple or black, and about 0.5
inches across. Mostly 13 overlapping yellow ray florets each about 1.25 inches long. Bracts
lanceolate and overlapping. Flower stalks 3.0-7.0 inches long. Zigzag upper stems on tallest flowering plants beginning at the upper ends of the inflorescence. Numerous thin flowering shoot.
Flowering Season: September to November.
Thirteen yellow ray florets
Southeastern sunflower blooms from Summer to fall
Bracts and rays
Zigzag upper stem and inflorescence
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a wild-flower garden or used as striking and colorful accent against a background of green
shrubs.
Scientific Name: Helianthus angustifolius
Additional Notes: A shorter species than
Range: New York to Florida as well as MisSoutheastern sunflower. It prefers moist soils
souri, Oklahoma and Texas
and is found in open fields, and roadsides. It
Life Cycle: Perennial
adapts to ordinary garden conditions and is very
Reproduction: Seeds; slender rhizomes
showy in late summer and fall. Individual flowHeight: 2 to 5 feet tall
ers droop soon after cutting, thus not recomCommon Use: Mass planting toward the rear of mended as cut flowers.
Swamp Sunflower; Narrowleaf
Sunflower
Hendry County. Mid-October
Glades County. Mid-October
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Swamp Sunflower; Narrowleaf Sunflower (Helianthus angustifolius)
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Stem: Usually unbranched. Approximately 0.25 inches diameter at the base narrowing to about
0.13 inches at the top of the stem where flowering begins.
Leaf Type: Numerous and mostly alternately arranged. Linear or narrowly lanceolate. Often
ribbed upper surface. Very rough to the touch. Dark green above, pale green beneath. Mostly 4.06.0 inches long and 0.2 inches wide. Ten to thirty times long as wide. Most without petioles
(sessile) or with very short ones.
Rhizomes
Roots
Roots and rhizomes
Many leaves to a stem
Basal stem
Linear ribbed leaves
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Swamp Sunflower; Narrowleaf Sunflower (Helianthus angustifolius)
Inflorescence: Usually 2.75-3.5 inches across. Disks red-purple, sometimes yellow, about 0.50.75 inches across. Generally 10-15 ray florets, upwards of 21, and up to 1.5 inches long. Bracts
seldom extend beyond the disk. Flower stalks mostly 4.0-5.0 inches long. Some stems with only a
single flower.
Flowering Season: September to November.
Fifteen yellow ray florets
Flowers
Bracts seldom extend beyond the disk
Long-stalked flowers
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Additional Notes: Beach sunflower naturally
occurs along the coast, but adapts well for
Scientific Name: Helianthus debilis
inland use. It is the most widely planted of the
Range: Florida, Alabama to Mississippi
Life Cycle: Annual where it is subject to frosts Helianthus. Highly salt tolerant, it does best in
full sun. The stems are easily rooted whenever
and freezes, otherwise a short-lived perennial
they touch the ground. Under adequate growing
Reproduction: Seeds; cuttings
condition it becomes a shrubby groundcover.
Height: 2 to 4 feet tall
Common Use: Groundcover, dune stabilizer, Heavy summer rains, especially in poorly
roadway medians, mass planting, border, cas- drained soils, promote root rot, defoliation, and
cading down a wall, edging, butterfly attractant elongated stem.
Beach Sunflower
Lee County. Early January
Lee County. Mid October
Lee County. Late November
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Beach Sunflower (Helianthus debilis)
Stem: More or less prostrate with ascending or erect flowering branches. Smooth to rough. Young
stems are green and sometimes mottled red-brown. Basal stems of the oldest plants are thick and
woody.
Leaf Type: Mostly opposite and rarely alternate. Lance-ovate and broadly tapering or somewhat
cordate at the base. Rough and hairy, entire or toothed. Usually 2.5-4.5 inches long, 1.5-3.5 inches
wide. Petioles mostly 0.6-2.75 inches long.
Green stem
Mottled stem
Woody basal stem
Opposite lanceolate shaped leaves
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Beach Sunflower (Helianthus debilis)
Inflorescence: Usually 2.0-2.25 inches across. Disks red-purple, about 0.5 inches wide. Rays yellow, about 1.0 inch long. Bracts widely-spaced tapering to a point. Thin flower stalks mostly 2.55.0 inches long.
Flowering Season. Blooms year-round in South Florida. Peak display in fall, winter and spring.
Central disk and ray florets
Widely spaced bracts
Flower stalks are usually from 2.25-5.0 inches
long
Lee County. Late December
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tection, beach beautification, solid waste reclamation sites. Attracts pollinators.
Scientific Name: Helianthus debilis subsp.
Additional Notes: This is an erect and hairy
cucumerifolious
form of the commonly planted beach sunflower.
Range: Florida, Texas
The plant is a perennial in southern Florida and
Life Cycle: Annual and perennial
is a reseeding annual throughout the rest of FlorReproduction: Seeds
ida. Adapted to well-drained nutrient poor soils.
Height: 2 to 6 or more feet tall
Found in full sun along roadsides, in ditches,
Common Use: Stabilizing back-dune areas of
coastal sand dunes, providing wind erosion pro- and by seashores.
Cucumberleaf Dune Sunflower
Pasco County. Late June
Bay County. Late August
Pasco County. Late June
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Cucumberleaf Dune Sunflower (Helianthus debilis subsp. cucumerifolius)
Stem: Erect, shiny and rough often with conspicuous mottled red-brown hairs.
Leaf Type: Mostly alternate. Lanceolate-ovate, or ovate with a cordate base, acute tip. Largely
hairy to the touch with a few smooth exceptions. Margin entire or variously toothed. Blades to 6.0
inches long. Petioles 0.4-2.75 inches long.
Mottled hairy stems and
hairy petiole
Hairy stem and hairy
petioles
Opposite lanceolate shaped leaves
Hairy stem and hairy petioles
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Cucumberleaf Dune Sunflower (Helianthus debilis subsp. cucumerifolius)
Inflorescence: Usually 2.50 inches across. Disk red-purple, about 0.5 inches wide. Rays yellow
mostly having 11-23 florets. Bracts taper to a point. The uppermost ones extend slightly beyond
the disk. Flower stalks thin and usually from 4-12 inches long. Solitary flowers or blooms on multi
-branching stems.
Flowering Season: Flowers year-round in warmest areas and March through November in Florida
Panhandle.
Central disk and ray florets
Unbranched flowering plant
Ray florets and bracts
Multi-branching plants
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Rayless Sunflower
Scientific Name: Helianthus radula
Range: South Carolina to Florida, west to
southeast Louisiana
Life Cycle: Perennial
Reproduction: Seeds
Height: 1 to 3.5 feet tall
Common Use: Cut flowers, mass planting
Additional Notes: The basal rosette of leaves
remains virtually hidden until the production of
a long flowering stem. The long leafless stem
and lack of petals makes it a good cut flower.
Performs best in slightly moist soil. Rayless sunflowers is frequent in wet flatwoods in the
northern counties of Florida south to the central
peninsula of Florida and Collier County.
Jeff Norcini
Liberty County. Late September
Stem: Erect, hairy, leafless, but with a reclined base. Emerges from the soil amongst basal leaves
to flower.
Leaf Type: Basal leaves arranged in rosettes, entire or nearly so. Blades approximately circular
(orbicular) or elliptic-orbicular to broadly obovate. Pubescent with coarse, stiff hairs. One and onehalf to four inches long, and 1.0-1.6 times as long as wide. Petioles very short or lacking.
Inflorescence: Disk deep purple, 0.6-1.0 inches wide. Ray florets none, or rarely present. Two to
three solitary flowers on a long, leafless flowering stem arising from the basal rosette.
Flowering Season: Summer.
Jeff Norcini
Craig Huegel
Rosette basal leaves
Without rays
Craig Huegel
With a few yellow rays
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floridanus. It is becoming popular as a garden
plant, which may increase its range. It is a wetScientific Name: Helianthus simulans
land species to be grown in full sun and moist
Range: Georgia to Louisiana
soil. Very noticeable from a distance. Prune top
Life Cycle: Perennial
1/3 of plant in early summer to encourage bushiReproduction: Seeds; short rhizomes
ness and more flowers. It explodes with color in
Height: 5 to 8.5 feet tall
the fall. This species, native from Georgia to
Common Use: Mass planting, cut flowers
Additional Notes: Muck sunflower is thought Louisiana, may have escaped cultivation in Florto be a stable hybrid of H. angustifolius and H. ida.
Muck Sunflower
Alachua County. Early November
Stem: Erect, hairy. Usually without basal leaves when flowering.
Leaf Type: Upper leaves alternate, lower opposite. Blades linear-lanceolate with tapering base.
Margins entire. Petioles 0.2-.0.4 inches long.
Old lower stems shed basal leaves at
flowering time
Alternating upper leaves
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Muck Sunflower (Helianthus simulans)
Inflorescence: Disk yellow to brownish with dark brown or dark purple anthers. Ray florets 1523. Flowers on 8-10 foot stems of 1-15 flowers.
Flowering Season: One of the latest sunflower to bloom, October and November.
Central disk and ray florets
Early October
Early October
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tant, birds strongly attracted to the seeds. For
added mid-summer color in partially shaded arScientific Name: Helianthus strumosus
Range: Eastern Canada, Northeastern U.S.A, eas.
North-Central U.S.A., Southeastern USA, South Additional Notes: An upland sunflower. Naturally occurring along woodland edges, forest
Central USA, Northern Florida
opening, and areas with dappled shade. Survives
Life Cycle: Perennial
in dense competition. Paleleaf Woodland sunReproduction: Seeds; rhizomes
flower does best with a few hours of direct
Height: 2 to 7 feet tall
Common Use: Wildlife habitat, butterfly attrac- sunlight each day. It dies back in the fall and reemerges in the spring.
Paleleaf Woodland Sunflower
Suwannee County. Late August
Stem: Thin, unbranched except where inflorescence is initiated. Smooth below the inflorescence
or with a few long hairs.
Leaf Type: Mostly opposite. Variable leaf shapes. Mainly broadly lanceolate to ovate, sometimes
broadly rounded at the base. Shallow toothed. Relatively thick and firm, coarse and rough to the
touch. Blades 3.2-8.0 inches long, 1.0-4.0 inches wide. Petioles 0.25-1.25 inches long.
Thin stem with opposite lanceolate leaves
Short petiole
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Paleleaf Woodland Sunflower (Helianthus strumosus)
Inflorescence: Disks with 35 or more florets surrounded by 10-20 yellow ray florets. Bracts, 1825, lanceolate and slightly spreading. The margins usually have fine hairs. They are relatively
short and not much exceeding the central disk. Flower heads occur in loose clusters at the tops of
stems.
Flowering Season: June to September.
Single flower. Suwannee County
Suwannee County. Late August.
Suwannee County. Late August.
Flower heads are in loose clusters
Disk and bracts without ray florets
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Typical Leaf Shapes of Six Helianthus
H. agrestis
H. angustifolius
H. debilis subsp. cucmerifolius
H. simulans
H. debilis
H. strumosus
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References
Bailey, L.H., and E.Z. Bailey.1996. Hortus Third, A Concise Dictionary of Plants Cultivated in the
United States and Canada, Cornell University, Ithaca, New York
Bell, R.C. and B.J. Taylor. 1982. Florida Wild Flowers and Roadside Plants. Laurel Hill Press,
Chapel Hill, North Carolina
Culbert, D. 2005. Falling for Yellow Wildflowers. University of Florida, IFAS Extension. Okeechobee County Extension, Okeechobee, Florida
Daniels, J. C. and S. Tekiela. Wildflowers of Florida: Field Guide. Adventure Publications, Inc.
Cambridge, Minnesota
Hammer, R.L. 2002. Everglades Wildflowers. A Field Guide to Wildflowers of the Historic Everglades, Including Big Cypress, and Fakahatchee Swamps. The Glove, Pequot Press, Guilford,
Connecticut
Huegel, C. 2009. Pineleaf Woodland Sunflower. Hawthorn Hill Native Wildflower and Rare Plant
Nursery.
Maura, C. and S. Sanders. 2002. Cucumberleaf Sunflower. USDA, Brooksville Plant Material
Center, Brooksville, Florida
Prairie Nursery. 2014. Woodland Sunflower—H. strumosus.
Schuyler, A. 1982. Wildflowers South Florida Natives: Identification and Habit of Indigenous
Tropical Flora. JMG Publication Corporation, Fort Lauderdale, Florida
Taylor, W.K. 2013. Florida Wildflowers: A comprehensive Guide. University Press of Florida,
Gainesville, Florida
Taylor, W.K. 1999. Florida Wildflowers, Their Natural Communities. University Press of Florida,
Gainesville, Florida
Taylor, W.K. 1992. The Guide to Florida Wildflowers. Taylor Trade Publishing, Lanham, New
York
Tobe, J.D. et al. 1998. Florida Wetland Plants: An Identification Manual. Florida Department of
Environmental Protection, Tallahassee, Florida
Toney, and A. Gray.1956. Helianthus debilis subsp. cucumerifolius. Flora of China.
Watson, E. 1929. Helianthus simulan. Flora of North America.
Wunderlin, R.P. and B.F. Hansen. 2008. Atlas of Florida Vascular Plants. Institute for Systematic
Botany, University of South Florida, Tampa, Florida
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Florida Flowering Plants Publications
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Firebush
Gaillardia
Mimosa
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Railroad Vine
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Tie Vine
Yellowtop
Flowering Trees Fact Sheets
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Swamp Lily
Flat-Topped Goldenrod
Gaillardia
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Queen’s Wreath
Railroad Vine Measurement
All pictures were taken by Stephen H. Brown except where indicated.
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by sending an email request to brownsh@ufl.edu. Include your first and last names and county,
state or country of residence.
This fact sheet was reviewed by Drs. Craig Huegel, Hawhtorn Hill Native Wildflower Nursery,
Seminole Florida and Jeff Norcini, OecoHort, Tallahassee, Florida; Peggy Cruz, Lee County Extension; Pat Rooney and Kim Cooprider, Lee County Master Gardeners and Jenny Evans, SanibelCaptiva Conservation Foundation.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information
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orientation, martial status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. 11/2014
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