Helianthus nuttallii
Fl. N. Amer. 2: 324. 1842.
Perennials, 100–400 cm (rhizomatous). 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. Heads 1–6. Peduncles 1–18 cm. Involucres hemispheric, 10–20 mm diam. 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. Paleae 8–12 mm, 3-toothed. 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. Cypselae 3–5 mm, glabrate; pappi of 2 aristate scales 2.2–4.5 mm plus 0–2 lanceolate scales 0.5–1 mm. 2n = 34 (subspecies unknown).
Distribution
Alta., B.C., Man., Ont., Que., Sask., Ariz., Calif., Colo., Idaho, Iowa, Kans., Minn., Mo., Mont., N.Dak., N.Mex., Nebr., Nev., Okla., Oreg., S.Dak., Utah, Wash., Wyo.
Discussion
Subspecies 3 (3 in the flora).
Selected References
None.
Lower Taxa
Key
| 1 | Leaves: abaxial faces tomentulose to villous-tomentose; phyllaries densely hairy (longer hairs 1+ mm) | Helianthus nuttallii subsp. parishii |
| 1 | Leaves: abaxial faces hispid to hispidulous; phyllaries ± glabrate (longer hairs 0.5–1 mm). | > 2 |
| 2 | Plants usually 200–300 cm; leaves mostly alternate, blades narrowly to broadly lanceolate,apices acute to acuminate | Helianthus nuttallii subsp. nuttallii |
| 2 | Plants usually 100–250 cm; leaves all or mostly opposite, blades lanceolate to nearly ovate, apices acute to obtuse | Helianthus nuttallii subsp. rydbergii |