Northern Prairie Wildlife Research Center
Sawtooth Sunflower (Helianthus grosseserratus)
- Family: Aster (Asteraceae)
- Flowering: July-October.
- Field Marks: This sunflower usually has several leaves alternate and usually at least 20 leaves per stem.
- Habitat: Wet meadows, along streams, around ponds; also in drier habitats.
- Habit: Perennial herb with extensive rhizomes.
- Stems: Erect, branched or unbranched, smooth and glaucous except for short hairs near the flowers, up to 12 feet tall.
- Leaves: Alternate or opposite, simple, lanceolate, pointed at the tip, tapering to the base, with or without teeth, usually somewhat hairy, up to 8 inches long, up to 2 inches broad.
- Flowers: Several crowded together into a head, with several heads per plant; each head up to 3 inches across, subtended by very narrow, pointed bracts, with 10-20 yellow rays and a central yellow disk.
- Sepals: 0.
- Petals: Some united to form yellow rays, others united to form yellow tubular flowers in a central disk.
- Stamens: 5.
- Pistils: Ovary inferior.
- Fruits: Achenes usually short-hairy.
- Notes: Martin and Hutchins in A Flora of New Mexico (1981) note that specimens from New Mexico called H. grosseserratus are actually H. nuttallii.
Previous Species -- Clammy Hedge-hyssop (Gratiola neglecta)
Return to Species List -- Group 7
Next Species -- Rough Sumpweed (Iva annua)