About Helianthus nuttallii Torr. & A.Gray
Common Name and Native Range
Helianthus nuttallii, commonly called Nuttall's sunflower, is a sunflower species native to northern, central, and western North America. Its native range extends from Newfoundland west to British Columbia, and south to Missouri, New Mexico, and California.
Plant Type and Height
This is a herbaceous perennial plant that grows 50–400 cm (20–160 inches) tall.
Leaf Arrangement
Its leaves are arranged oppositely on the lower section of the stem, and alternately higher up on the stem.
Leaf Characteristics
The leaves are narrow and lanceolate, 8–20 cm (3.2–8.0 inches) long and 6–30 mm wide, with a rough texture.
Flowerhead Size and Color
The species produces yellow flowers in flowerheads approximately 9 cm (3.6 inches) in diameter.
Floret and Flowerhead Count
Each flowerhead holds 10–20 ray florets and at least 60 disc florets, and each stem bears one to a few flowerheads.
Subspecies Count
There are three recognized subspecies of Helianthus nuttallii.
Subspecies nuttallii Distribution
First is Helianthus nuttallii subsp. nuttallii, which is distributed across Canada and the western United States.
Subspecies nuttallii Taxonomic Status
This taxon is classified by some authorities as a synonym of the full Helianthus nuttallii species, while other authorities consider it a distinct subspecies. It belongs to the genus Helianthus within the family Asteraceae.
Subspecies parishii Common Name
Second is Helianthus nuttallii subsp. parishii (A.Gray) Heiser, commonly called the Los Angeles sunflower.
Subspecies parishii Distribution and Conservation Status
This subspecies is endemic to Southern California, and it has been presumed extinct since 1937.
Subspecies rydbergii Distribution
Third is Helianthus nuttallii subsp. rydbergii (Britton) R. Long, which is distributed in central Canada and the interior northwestern United States.
