Helianthus praecox

Helianthus praecox
Conservation status
	; Least Concern (IUCN 2.3)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Asterales
Family:	Asteraceae
Genus:	Helianthus
Species:	H. praecox
Binomial name
	Helianthus praecox; Engelm. & A.Gray
Synonyms
	Synonymy Helianthus cucumerifolius var. praecox (Engelm. & A.Gray) A.Gray ; Helianthus debilis subsp. praecox (Engelm. & A.Gray) Heiser ; Helianthus debilis subsp. hirtus Heiser, syn of subsp. hirtus ; Helianthus debilis subsp. runyonii Heiser, syn of subsp. runyonii ; Helianthus praecox var. runyonii (Heiser) B.L.Turner, syn of subsp. runyonii ;

Helianthus praecox is a North American species of sunflower known by the common name Texas sunflower. It is endemic to Texas. Most of the populations are either along the Gulf Coast or in the Río Grande Valley.^[2]

Helianthus praecox grows on sandy soils and coastal prairies. It is an annual herb up to 150 cm (60 inches or 5 feet) tall. One plant usually produces 1-3 flower heads, each containing 11-16 yellow ray florets surrounding 35 or more red or purple disc florets.^[3]

Subspecies^[1]^[3]^[4]

Helianthus praecox subsp. hirtus (Heiser) Heiser - near Carrizo Springs in Dimmit County
Helianthus praecox subsp. praecox - sandy soils along the coast in Galveston County + Brazoria County
Helianthus praecox subsp. runyonii (Heiser) Heiser - Coastal prairies (from Calhoun County to Cameron County) and Río Grande Valley (from Webb County to Cameron County)

References

^ ^a ^b The Plant List, Helianthus praecox Engelm. & A.Gray
^ Biota of North America Program 2014 county distribution map
^ ^a ^b Flora of North America, Helianthus praecox Engelmann & A. Gray, 1847. Texas sunflower
^ Billie L. Turner. 2014. Taxonomy of the Texas sunflower (Helianthus praecox) Asteraceae. Phytologia (April 1, 2014) 96(2) 107 includes county-level range map for all 3 subspecies

External links

William Carr, University of Texas, Helianthus praecox var. runyonii [Asteraceae] – Runyon's sunflower photos

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[austin-1] The Plant List, Helianthus praecox Engelm. & A.Gray

[2] Biota of North America Program 2014 county distribution map

[crockett-3] Flora of North America, Helianthus praecox Engelmann & A. Gray, 1847. Texas sunflower

[4] Billie L. Turner. 2014. Taxonomy of the Texas sunflower (Helianthus praecox) Asteraceae. Phytologia (April 1, 2014) 96(2) 107 includes county-level range map for all 3 subspecies

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