Plant Species: Helianthus annuus, common sunflower
Kingdom: Plantae
Phylum: Magnoliophyta -- flowering plants
Class: Magnoliopsida -- dicotyledons
Order: Asterales
Family: Asteraceae (Compositae) -- sunflower
Genus: Helianthus
Species: annuus
Variety:
Common Name: common sunflower
Species Code: HEAN3
Origin: Native to dry, open places over much of central and western North America and naturalized farther east.
Locally it is mostly a species of the canyon grasslands and adjacent areas . It is sometimes seen on the Palouse, usually along roadsides where seed was probably deposited
by a vehicle or other machinery. It rarely persists in such situations.
Rare: no
Form: forb, annual, coarse, 20-120 cm tall, rough-hairy overall; stems simple or branched.
Duration: annual
Longevity: annual
Habitat Type: canyon grasslands
Wetland Indicator Status: FACU+
Leaves: mostly alternate (the lowermost opposite), petiolate, dentate, ovate or broader, the lower often cordate.
Mature height: 8-48 inches
Flowers: heads large, terminal; involucre 10-12 mm tall, bracts subequal or imbricate, ovate or ovate-oblong, tip acuminate, hispid or hirsute, margins ciliate; ray flowers up to 3 cm long, yellow, neutral, disc flowers reddish brown to occasionally yellow, perfect, 5-8 mm long.
Flower color: yellow
Bloom: July, August, September
Bloom starts on:
Bloom ends on:
Fruit: achene, glabrous, 4 mm or longer, gray; pappus of 2 deciduous bristles.
Vegetation type:
Characteristics:
A highly variable species but no infraspecific taxa are widely recognized.
69,049 seeds/lb (Stevens 1932).
32,000-66,176 seeds/lb (Hassell et al 1996).
46,919 seeds/lb (USDA NRCS PLANTS Database 2009).
Reproduces sexually by seed.
n=17 (Flora of North America Editorial Committee 1993, University of British Columbia 2003, Baldwin et al 2004).
Fruit is an achene.
Disc flowers are perfect, ray flowers are neutral.
Achenes are edible and used by humans as well as wildlife. Various plant parts are used medicinally.
Comments: The species is widely cultivated and many selections have been made and cultivars named.
Sun requirement: full
Soil moisture: xeric
Precipitation: 12-60 inches (USDA NRCS PLANTS Database 2009).
Fire:
Hazards:
Sowing time: spring
Transplant time:
Stratification: none
Seed yield: high
Seed harvest: easy
Seed first harvest: annual
Seed cleaning: easy
Planting duration: annual
Seed insect problem:
Seed shatter: low
Seed size: large
Seed harvest date:
Seed comments:
Key words: native upland annual forb
Alternate Genus:
Alternate Species:
Alternate Variety:
Propagation:
Seed germinates readily without pretreatment.
Seed is stored in the seed bank for 3-5 years (Burnside et al 1981, Snow et al 1998).
Reproduces sexually by seed.
Notes: Persistent in the canyon grasslands and adjacent areas only.
References:
Baldwin, B.G., S. Boyd, B.J. Ertter, D.J. Keil, R.W. Patterson, T.J. Rosatti, and D.H. Wilken (eds). 2004. Jepson Online Interchange for California Floristics. University and Jepson Herbaria, University of California, Berkeley, CA. Accessed 9/22/09 online at http://ucjeps.berkeley.edu/interchange.html
Burnside, O. C., C. R. Fenster, L. L. Evetts, and R. R. Mumm. 1981. Germination of Exhumed Weed Seed in Nebraska. Weed Sci. 29:577-586.
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 7+ vols. New York and Oxford. Oxford University Press. Online at http://www.fna.org/FNA/
Hassell, Wendell, W. Rocky Beavers, Steve Ouellette, and Thomas Mitchell. 1996. Seeding Rate Statistics for Native and Introduced Species. US Department of Interior and US Department of Agriculture, NRCS. Denver, CO.
Snow, A.A., P. Moran-Palma, L.H. Riesenberg, A. Wszelaki, and G.J. Seiler. 1998. Fecundity, Phenology, and Seed Dormancy of F1 Wild-crop Hybrids in Sunflower (Helianthus annuus, Asteraceae). American Journal of Botany 85:794-801.
Stevens, O.A. 1932. The Number and Weight of Seeds Produced by Weeds. American Journal of Botany 19:784-794.
USDA NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 22 September 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
University of British Columbia. 2003. British Columbia Flora. University of British Columbia Botanical Garden and Centre for Plant Research. Online at http://www.bcflora.org/ Accessed 9/22/09.