Helianthus pauciflorus

Nuttall

Gen. N. Amer. Pl. 2: 177. 1818.

Endemic
Treatment appears in FNA Volume 21. Treatment on page 160. Mentioned on page 144, 161, 162.

Perennials, 50–200 cm (rhizomatous). Stems erect, scabro-hispid. Leaves mostly basal; opposite, or opposite (proximal) and alternate; petioles 0–1 cm; blades lance-ovate to oblong-lanceolate, or rhombic-ovate to lance-linear, 5–27 × 2–6 cm, bases cuneate, margins serrate to subentire, abaxial faces sparsely hispid, sparsely, if at all, gland-dotted (cauline smaller). Heads 1–10. Peduncles 3–12 cm. Involucres hemispheric, 15–23 mm diam. Phyllaries 25–35, ovate, 6–10 × 3–5 mm, (margins ciliate) apices acute, abaxial faces glabrate to hispid. Paleae 9–10 mm, shallowly 3-toothed to subentire (apices ciliate, hairy). Ray florets 10–20; laminae 20–35 mm (abaxial faces usually gland-dotted). Disc florets 75+; corollas 6.5–7 mm, lobes usually reddish, sometimes yellow; anthers dark, appendages dark (style branches yellow). Cypselae 5–6 mm, glabrate; pappi of 2 aristate scales 4.5–5 mm plus 1–4 smaller aristate scales 0.3–2 mm. 2n = 102 (subspecies unknown).

Distribution

V21-385-distribution-map.gif

Alta., B.C., Man., N.B., N.S., Ont., P.E.I., Que., Sask., Ark., Colo., Conn., Ga., Ill., Ind., Iowa, Kans., Ky., Maine, Mass., Mich., Minn., Mo., Mont., N.Dak., N.H., N.J., N.Mex., Nebr., Okla., Pa., R.I., S.Dak., Tex., Va., Vt., Wis., Wyo.

Discussion

Subspecies 2 (2 in the flora).

Variation within Helianthus pauciflorus is complex and is complicated by hybridization with H. tuberosus. Hybrids with H. tuberosus are known as H. ×laetiflorus, which is frequently cultivated.

Selected References

None.

Key

1 Plants 80–200 cm; leaves usually alternate distally, blades oblong-lanceolate to lance-ovate, 8–27 cm, apices acuminate Helianthus pauciflorus subsp. pauciflorus
1 Plants 50–120 cm; leaves opposite, blades rhombic-ovate to lance-linear, 5–12 cm, apices acute or obtuse Helianthus pauciflorus subsp. subrhomboideus
... more about "Helianthus pauciflorus"
Edward E. Schilling +
Nuttall +
Alta. +, B.C. +, Man. +, N.B. +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Ark. +, Colo. +, Conn. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, Maine +, Mass. +, Mich. +, Minn. +, Mo. +, Mont. +, N.Dak. +, N.H. +, N.J. +, N.Mex. +, Nebr. +, Okla. +, Pa. +, R.I. +, S.Dak. +, Tex. +, Va. +, Vt. +, Wis. +  and Wyo. +
Gen. N. Amer. Pl. +
Undefined (tribe Undefined) subtribe Lagasceinae +
Helianthus pauciflorus +
Helianthus +
species +