Helianthus occidentalis

Riddell

W. J. Med. Phys. Sci. 9: 577. 1836.

Common names: Western sunflower
Endemic
Treatment appears in FNA Volume 21. Treatment on page 160. Mentioned on page 144, 146, 147, 156, 163.

Perennials, 60–150 cm (rhizomatous, sometimes stoloniferous as well). Stems (often reddish) erect, pilose to appressed-hairy proximally. Leaves mostly basal; opposite; petioles 2.5–10 cm; blades oblong-lanceolate or elliptic to ovate, 5–20 × 1.5–7 cm, bases cuneate, margins entire or serrulate, abaxial faces scabrous to hispidulous, gland-dotted (cauline usually smaller, rarely 2–4 pairs well developed). Heads 1–4(–12). Peduncles 1–14 cm. Involucres cylindric, 9–14 mm diam. Phyllaries 20–25, lanceolate, 4.5–7(–11) × 1.5–2.5 mm, (margins usually ciliate) apices acute to short-acuminate, abaxial faces glabrate to sparsely pilose (hairs moniliform), not gland-dotted. Paleae 5–7 mm, subentire to 3-toothed (shortly mucronate). Ray florets 8–14; laminae 18–22 mm (abaxial faces densely gland-dotted). Disc florets 50+; corollas 4.5–5.5 mm, lobes yellow; anthers dark brown or black, appendages yellow. Cypselae 3–4(–5) mm, sparsely villous or glabrate; pappi of 2 aristate scales 1.5–2.8 mm plus 0–4 deltate scales 0.4–1 mm. 2n = 34 (subspecies unknown).

Distribution

V21-382-distribution-map.gif

Ark., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Mass., Md., Mich., Mo., N.C., N.J., Ohio, Pa., S.C., Tenn., Tex., Va., W.Va., Wis.

Discussion

Subspecies 2 (2 in the flora).

Selected References

None.

Key

1 Leaves entire or nearly so, scabrous or hirsute, rough to touch Helianthus occidentalis subsp. occidentalis
1 Leaves usually serrate, strigose or glabrous, smooth to touch Helianthus occidentalis subsp. plantagineus
... more about "Helianthus occidentalis"
Edward E. Schilling +
Riddell +
Western sunflower +
Ark. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, Mass. +, Md. +, Mich. +, Mo. +, N.C. +, N.J. +, Ohio +, Pa. +, S.C. +, Tenn. +, Tex. +, Va. +, W.Va. +  and Wis. +
W. J. Med. Phys. Sci. +
Undefined (tribe Undefined) subtribe Lagasceinae +
Helianthus occidentalis +
Helianthus +
species +