Helianthus pauciflorus Nutt.
Source: USDA Plants_111306
Family: Asteraceae
Stiff Sunflower
Helianthus pauciflorus image
Peter Gorman  
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). 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.

Perennial with long rhizomes; stems scabrous or hispid to subglabrous, ±naked above, the heads long-pedunculate; lvs nearly all opposite, to 15 pairs below the infl, scabrous to shortly hispid on both sides, mostly (2-)2.5-8 times as long as wide, mostly trinerved, toothed or entire, tapering to a short petiole or petiolar base, the middle ones seldom much smaller than the lowest ones present at anthesis; disk red-purple, 1.5-2.5(-3) cm wide; invol bracts evidently imbricate, broad, firm, appressed, mostly ovate or broadly lanceolate, sharply acute to obtuse, conspicuously ciliolate, otherwise generally glabrous; rays 10-21, 1.5-3(-3.5) cm; pappus nearly always with some short scales in addition to the 2 longer awns; 2n=102. Prairies and roadsides; Mich. and Ind. to Alta., N.M., and Tex., and e. occasionally to Mass. and N.B. Aug., Sept. Two vars.:

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.
Helianthus pauciflorus image
Frank Mayfield  
Helianthus pauciflorus image
Frank Mayfield  
Helianthus pauciflorus image
Frank Mayfield  
Helianthus pauciflorus image
Frank Mayfield  
Helianthus pauciflorus image
Frank Mayfield  
Helianthus pauciflorus image
Helianthus pauciflorus image
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Helianthus pauciflorus image
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