''Helianthus porteri'' is a species of
sunflower
The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage (as a meal or a silage plant), as ...
known by the common names Porter's sunflower, Stone Mountain daisy and Confederate daisy. The term "daisy" is a imprecise because the species is a sunflower (''
Helianthus
''Helianthus'' () is a genus comprising about 70 species of annual and perennial flowering plants in the daisy family Asteraceae commonly known as sunflowers. Except for three South American species, the species of ''Helianthus'' are native to ...
'') rather than a daisy (''
Bellis
''Bellis'' () is a genus of flowering plants in the family Asteraceae.
The group is native to Europe, the Mediterranean and northern Africa. One species has been introduced into North America and others into other parts of the world. The genus ...
'' and related genera). Likewise, although the plant grows on
Stone Mountain
Stone Mountain is a quartz monzonite dome Inselberg, monadnock and the site of Stone Mountain Park, east of Atlanta, Georgia. Outside the park is the small city of Stone Mountain, Georgia. The park is the most visited tourist site in the state o ...
, GA, its range extends well beyond. The connection to the
Confederacy is through Stone Mountain which contains a confederate monument, although the connection is tenuous as the species was named before the Civil War in 1849 by Harvard botanist
Asa Gray
Asa Gray (November 18, 1810 – January 30, 1888) is considered the most important American botanist of the 19th century. His ''Darwiniana'' was considered an important explanation of how religion and science were not necessarily mutually excl ...
in honor of
Thomas Conrad Porter
Thomas Conrad Porter (1822–1901) was an American botanist and theologian known as an expert on the flora of Pennsylvania.
Biography
Porter was born in Alexandria, Pennsylvania on January 22, 1822. He attended Harrisburg Academy before e ...
, a Pennsylvanian minister and botanist who collected the plant in Georgia. Gray initially named the plant ''Rudbeckia porteri'', changed to ''Helianthus'' in 1998 by John F. Pruski. The common name Porter's sunflower therefore most closely accords with the history of botanical discovery and naming.
The species is native to the southeastern United States, such as
Alabama
(We dare defend our rights)
, anthem = "Alabama (state song), Alabama"
, image_map = Alabama in United States.svg
, seat = Montgomery, Alabama, Montgomery
, LargestCity = Huntsville, Alabama, Huntsville
, LargestCounty = Baldwin County, Al ...
and
Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to the ...
, but has been introduced to granite outcrop areas in
North Carolina
North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...
where it is aggressively weedy.
''Helianthus porteri'' grows on thin soils on and around flat rock
granite
Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...
and
gneiss
Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures an ...
outcrops. It is an annual herb up to 100 cm (40 inches) tall. One plant usually produces 5 or more
flower heads
A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...
, each containing 7 or 8 yellow
ray florets
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...
surrounding 30 or more yellow
disc floret
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...
s.
Blake, Sydney Fay 1918. Contributions from the Gray Herbarium of Harvard University 54: 114–115
as ''Viguiera porteri''
References
External links
*
photo of herbarium specimen at Missouri Botanical Garden, collected in Georgia in 1846, isotype of ''Rudbeckia porteri/Viguiera porteri/Helianthus porteri''
Scott D. Gevaert, Jennifer R. Mandel, John M. Burke, and Lisa A. Donovan. 2013. High Genetic Diversity and Low Population Structure in Porter’s Sunflower ''(Helianthus porteri).'' Journal of Heredity 2013:104(3):407–415
doi:10.1093/jhered/est009
* ttp://www.floraofalabama.org/Plant.aspx?id=1059 Alabama Plant Atlas, ''Helianthus porteri''
porteri
Flora of the Southeastern United States
Plants described in 1849
Flora without expected TNC conservation status
{{Heliantheae-stub