Helianthus strumosus

Linnaeus

Sp. Pl. 2: 905. 1753

Common names: Rough sunflower hélianthe scrofuleux
Endemic
Synonyms: Helianthus montanus E. Watson Helianthus saxicola Small
Treatment appears in FNA Volume 21. Treatment on page 159. Mentioned on page 146, 158, 162.

Perennials, 100–200 cm (rhizomatous). Stems erect, glabrous or glabrate. Leaves cauline; mostly opposite, sometimes alternate (distal); petioles 1–3 cm; blades (light to dark green, 3-nerved distal to bases) lanceolate to lance-ovate or ovate, 7–18 × 2–10 cm, bases subcordate to ± cuneate, margins entire to ± serrate, abaxial faces glabrous or tomentulose, usually densely gland-dotted. Heads 3–15. Peduncles 1–9 cm. Involucres cylindric to hemispheric, 8–20 mm diam. Phyllaries 18–25 (erect, loose, or squarrose), lanceolate, 5.5–10 × 1.5–3 mm (equaling or slightly surpassing discs), (margins usually ciliate) apices acute to acuminate, abaxial faces glabrous or hispidulous, usually not gland-dotted. Paleae 5.3–6.5 mm, 3-toothed. Ray florets 10–20; laminae ca. 12–20(–30) mm. Disc florets 35+; corollas 5.5–6.5 mm, lobes yellow; anthers dark, appendages dark or reddish brown. Cypselae 4–5.5 mm, glabrate; pappi of 2 aristate scales (1–)2–2.5 mm. 2n = 68, 102.


Phenology: Flowering late summer–fall.
Habitat: Woods, roadsides, prairies
Elevation: 0–1500 m

Distribution

V21-380-distribution-map.gif

Ont., Que., Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.

Discussion

Helianthus strumosus is variable, particularly for leaf shape and indument; sufficient study has not been undertaken to evaluate whether regional forms deserve taxonomic recognition. Hybridization with other polyploids, including H. decapetalus, H. hirsutus, and H. tuberosus, further complicates the situation. It differs from H. tuberosus in having glabrous (or glabrate) stems and in lacking tubers.

Selected References

None.

Lower Taxa

None.

... more about "Helianthus strumosus"
Edward E. Schilling +
Linnaeus +
Rough sunflower +  and hélianthe scrofuleux +
Ont. +, Que. +, Ala. +, Ark. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, N.H. +, N.J. +, N.Y. +, N.C. +, N.Dak. +, Ohio +, Okla. +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +, W.Va. +  and Wis. +
0–1500 m +
Woods, roadsides, prairies +
Flowering late summer–fall. +
Helianthus montanus +  and Helianthus saxicola +
Helianthus strumosus +
Helianthus +
species +