Northern Prairie Wildlife Research Center
Western Wetland Flora
Field Office Guide to Plant Species
Helianthus nuttallii Torr. & Gray
- Family: Composite (Compositae)
- Flowering: July-November
- Field Marks: This tall sunflower has yellow flower heads up to 2 1/2 inches wide. The bracts that subtend the flower heads may be as long as 1 inch.
- Habitat: Moist or dry meadows.
- Habit: Perennial herb with thickened roots and short rhizomes.
- Stems: Upright, branched or unbranched, up to 12 feet tall, smooth or less commonly
hairy, more or less glaucous.
- Leaves: All opposite, or the uppermost alternate, simple, narrowly lanceolate to lanceolate, up to 6 inches long, up to 1 1/2 inches wide, pointed at the tip, tapering to the sessile or short-stalked base, with or without teeth, short-hairy and
- Flowers: Many crowded together into heads up to 2 1/2 inches across, each head consisting of 12-20 yellow rays and a central disk of yellow-tubular flowers; bracts surrounding the heads elongated, pointed at the tip, rough-hairy, up to 1 inch lo
- Sepals: 0.
- Petals: 5, yellow, some of them united to form rays, others united to form tubular flowers that comprise the central disk.
- Stamens: 5.
- Pistils: Ovary inferior.
- Fruits: Achenes ellipsoid, up to 1/6 inch long, smooth.
- Notes: The achenes are eaten by birds.
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