Helianthus nuttallii |
Helianthus nuttallii subsp. rydbergii |
|||||||||
---|---|---|---|---|---|---|---|---|---|---|
hélianthe de Nuttall, Nuttall's sunflower |
Nuttall's sunflower, Rydberg's sunflower |
|||||||||
Habit | Perennials, 100–400 cm (rhizomatous). | Plants usually 100–250 cm. | ||||||||
Stems | (usually yellow-brown or greenish, sometimes glaucous) erect, glabrous, hispid, ± hirsute, or scabrous. |
|||||||||
Leaves | cauline; all or mostly opposite to mostly alternate; petioles 0.5–1.5 cm; blades light to dark green, 3-nerved (distal to bases) ± lanceolate to ± ovate, 4–20 × 0.8–4 cm, bases cuneate, margins entire or ± serrate (flat), abaxial faces hispid to hispidulous or tomentulose to villous-tomentose, gland-dotted. |
all or mostly opposite; blades lanceolate to nearly ovate, apices acute to obtuse, abaxial faces hispid to hispidulous. |
||||||||
Peduncles | 1–18 cm. |
|||||||||
Involucres | hemispheric, 10–20 mm diam. |
|||||||||
Ray florets | 10–21; laminae 20–25 mm (abaxial faces not gland-dotted). |
|||||||||
Disc florets | 60+; corollas 5–7 mm, lobes yellow; anthers dark brown to black, appendages yellow. |
|||||||||
Phyllaries | 30–38 (loose, spreading), lanceolate to lance-ovate, 8–16 × 1.5–3 mm, (margins ciliate) apices acute to acuminate, abaxial faces usually ± strigose, rarely glabrate, not gland-dotted. |
abaxial faces ± glabrate or sparsely hairy (longer hairs 0.5–1 mm). |
||||||||
Heads | 1–6. |
|||||||||
Cypselae | 3–5 mm, glabrate; pappi of 2 aristate scales 2.2–4.5 mm plus 0–2 lanceolate scales 0.5–1 mm. |
|||||||||
Paleae | 8–12 mm, 3-toothed. |
|||||||||
2n | = 34 (subspecies unknown). |
|||||||||
Helianthus nuttallii |
Helianthus nuttallii subsp. rydbergii |
|||||||||
Phenology | Flowering late summer–fall. | |||||||||
Habitat | Open areas, sandy dry soils, wet places | |||||||||
Elevation | 200–1000 m (700–3300 ft) | |||||||||
Distribution |
AZ; CA; CO; IA; ID; KS; MN; MO; MT; ND; NE; NM; NV; OK; OR; SD; UT; WA; WY; AB; BC; MB; ON; QC; SK
|
CO; IA; MN; MT; ND; NE; SD; AB; MB; ON; QC; SK |
||||||||
Discussion | Subspecies 3 (3 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|||||||||
Key |
|
|||||||||
Source | FNA vol. 21, p. 166. | FNA vol. 21, p. 167. | ||||||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Helianthinae > Helianthus | Asteraceae > tribe Heliantheae > subtribe Helianthinae > Helianthus > Helianthus nuttallii | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | H. rydbergii | |||||||||
Name authority | Torrey & A. Gray: Fl. N. Amer. 2: 324. (1842) | (Britton) R. W. Long: Brittonia 18: 77. (1966) | ||||||||
Web links |
|