Helianthus nuttallii, or Nuttall's sunflower, is a species of sunflower native to northern, central, and western North America, from Newfoundland west to British Columbia, south to Missouri, New Mexico, and California.
Helianthus nuttallii is a herbaceous perennial plant growing to 50–400 cm (20-160 inches) tall. The leaves are opposite on the lower part of the stem, alternate higher up, narrow lanceolate, 8–20 cm (3.2-8.0 inches) long and 6–30 mm wide, with a rough texture. The flowers are yellow, produced in a flowerhead approximately 9 cm (3.6 inches) diameter with 10–20 ray florets and at least 60 disc florets; each stem bears one to a few flowerheads.Jepson Flora: Helianthus nuttalliiPlants of British Columbia: Helianthus nuttallii
Subspecies of Helianthus nuttallii include: Helianthus nuttallii subsp. nuttallii - Canada, western United States. is a subspecies of Helianthus nuttallii in the genus Helianthus in the family Asteraceae.Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, editors. 2012. "The Jepson Manual: vascular plants of California", second edition. University of California press, Berkeley. . pp 344 H. nuttallii subsp. nuttallii is considered by some to be a synonym for H. nuttallii. However, others argue that it is distinct from the species.Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, editors. 2012. "The Jepson Manual: vascular plants of California", second edition. University of California press, Berkeley. . pp 344 Helianthus nuttallii subsp. parishii (A.Gray) Heiser - (Los Angeles sunflower). Southern California, endemic. The subspecies is presumed to be extinct since 1937.Calflora taxon report, University of California, Helianthus nuttallii Torrey & A. Gray ssp. parishii (A. Gray) Heiser, Los Angeles sunflower, Parish's sunflower Helianthus nuttallii subsp. rydbergii (Britton) R. Long. - Central Canada, interior northwestern United States
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