Helianthus angustifolius
L.
Narrow-leaved Sunflower, Swamp
Sunflower
The cheerful disposition of this bright flower has made it a favorite among flower-lovers worldwide. With its smiling face turned up to the sun it is easy to understand why!
*photograph courtesy of John Pickering, Ecology Dept. University of Georgia, Athens, Georgia
... click on the photograph for
a more accurate photo and for an even more complex picture click here
Table of Contents
Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Order: Compositae
Family: Asteraceae
Subfamily: not found
Tribe: not found
Genus: Helianthus
Height:
6-8'
Flower Color: yellow-gold with
brown centers
Flower size: 2-3' diameter
Foliage: 4-6" narrow, dark green
leaves
Fruit: dry seeds produced in late
Fall
Sunflowers (Helianthus
sp.) belong to the largest order of flowering plants, the Compositae.
Members of this order are characterized by the crowding together of individual
flower heads. The heads of the flower are surrounded by tiny "leaflets"
that protect forming buds. The flowers open in succession, beginning
in the outer ring and moving inwards. The outer petals are larger
than the inner ones, giving the appearance of a sunburst. It is not
surprising that the Neo-Latin genus name helianthus means "sunflower"
The species Helianthus angustifolius was first described by Carl von Linnaeus in 1753 in England. A lectotype of the flower can be found at the Harvard University Herbaria.
*photograph used with permission
of Mike Baker (link provided in References)
|
|
|
|
| North America:
Continental United States; Canada |
|
Niering & Olmstead 1979 |
| Eastern North America:
United States east of Mississippi; Ontario and Eastern Canada |
|
Niering & Olmstead 1979 |
| Southeastern United States:
AL, AR, DE, DC, FL, GA, KY, MD, NC, SC, TN, VA, WV |
|
Niering & Olmstead 1979 |
| Coastal Plain |
|
Radford et al 1968 |
| Piedmont |
|
Duncan & Kartesz 1981 |
| Blue Ridge Mountains |
|
Duncan & Kartesz 1981 |
| Great Smoky Mountains National Park |
|
Radford et al 1968 |
| Ridge and Valley |
|
Duncan & Kartesz 1981 |
| Cumberland Plateau |
|
Duncan & Kartesz 1981 |
| Georgia |
|
Radford, Ahles & Bell 1968 |
| Clarke County, Georgia |
|
Dirr 1986 |
Growing
Conditions:
Uses:
"The outer ray
flowers are pistillate, having a pistil but no stamens, while the central
disc flowers are hermaphrodite. The inferior ovary contains one ovule
(attached to the base of the chamber) which ripens to form a dry one-seeded
fruit, filled with an embryo.
The flower-heads
of the sunflower are well-suited for insect pollination as the crowding
of the flowers ensures conspicuousness and the pollination of a maximum
number of flowers by a single insect visit. The honey, secreted at
the base of the style, is protected by the corolla tube from visits of
short-tongued insects. When the flower open the receptive surfaces
of the two stigmas are pressed together and occupy a position at the base
of the tube formed by the united anthers; the latter split on the inside
and the liberated pollen fills the cavity of the tube and exposes it to
contat with visiting insects. Fianll, the style protrudes right throught
the anther tube and the stigmas spread apart and expose their formerly
hidden receptive surfaces. Thus, the life history of the flower falls
into two stages, the first male and the second female. This favours
cross-pollination as compared to self-pollination. The sun-flower
is therefore practically self-sterile, though self-pollination may take
place at a late stage, when cross-pollination has failed."
*excerpt taken from E.
F. Hurt's Sunflower
Social History
Most sunflowers of today are thought to have originated in Peru or Mexico. The flower spread to the Southwestern United States by natural means but was introduced into Europe by the Spaniards of the 16th Century. The flower was first domesticated by Native Americans in America and used for food, dye, and medicinal purposes.
Many sunflower
varieties are grown primarily to harvest seeds, the oil of which is a booming
international business. Helianthus angustifolius, however,
produces unusually small seeds from which little oil can be extracted.
Therefore, it is admired largely for its ease of cultivation and hardy
beauty.
Helianthus angustifolius is quite abundant in the Eastern United Sates (though only moderately so in mountainous areas). It is extremely sparse in Western States, probably due to its unusual need for high moisture. It favors bogs and marshes that recieve heavy sun exposure, but can usually be seen growing wild in any sun-soaked place. Blooming season is limited primarily to the month of October though the plant will remain green in all frost-free weather. The best place to encounter a smiling sunflower, however, is in your own garden. The Swamp Sunflower requires hardly any attention after being planted and adds a bright spot to any yard!
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