Helenium autumnale |
Helenium flexuosum |
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common sneezeweed, fall sneezeweed, hélénie automnale, large-flower sneezeweed, mountain sneezeweed |
hélénie nudiflore, purple sneezeweed, purple-head sneezeweed |
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Habit | Perennials, 50–130 cm. | Perennials, 30–100 cm. |
Stems | 1(–7), branched distally, strongly winged, sparsely to densely hairy proximally, moderately to densely hairy distally. |
usually 1, usually branched distally, strongly winged, glabrous or sparsely hairy proximally, sparsely to moderately hairy distally. |
Leaves | usually moderately to densely hairy, sometimes glabrous; basal blades (withered by flowering) lanceolate, oblanceolate, or obovate, entire or weakly lobed; proximal and mid blades obovate to oblanceolate, usually dentate or entire; distal blades oblanceolate to lanceolate, entire or dentate. |
glabrous or sparsely to moderately hairy; basal blades oblanceolate to obovate or spatulate, entire or serrate; proximal and mid blades oblanceolate to lanceolate, entire or toothed; distal blades lanceolate to lance-linear, entire. |
Peduncles | 3–10 cm, moderately to densely hairy. |
3–10 cm, sparsely to moderately hairy. |
Involucres | globoid, 8–20 × 8–23 mm. |
globoid to usually ovoid, 8–17 × 9–17 mm. |
Ray florets | 8–21, pistillate, fertile; corollas yellow, 10–23 × 4–10 mm. |
usually 8–13, neuter, sometimes 0; corollas yellow to reddish brown to red to purple, 10–20 × 5–10 mm. |
Disc florets | 200–400(–800+); corollas yellow proximally, yellow to yellow-brown distally, 2.4–4 mm, lobes 5. |
250–500(–700+); corollas yellow proximally and purple distally or purple throughout, 2.3–3.7 mm, lobes 4(–5). |
Phyllaries | (connate proximally) moderately to densely hairy. |
(connate proximally) moderately to densely hairy. |
Heads | 5–70(–100+) per plant, in paniculiform arrays. |
(1–)5–50(–80+) per plant, in paniculiform arrays. |
Cypselae | 1–2 mm, sparsely to moderately hairy; pappi of 5–7 entire, aristate scales (0.5–)0.9–1.5(–1.8) mm. |
1–1.2 mm, moderately hairy; pappi of 5–6 entire, aristate scales 0.6–1(–1.7) mm. |
2n | = 32, 34, 36. |
= 28. |
Helenium autumnale |
Helenium flexuosum |
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Phenology | Flowering (Jul–)Aug–Oct(–Nov). | Flowering (Apr–)May–Jul(–Oct). |
Habitat | Roadsides, fields, along streams, ditches, seepage areas, around ponds and lakes | Ditches, fields, washes, along streams |
Elevation | 20–2600 m (100–8500 ft) | 10–900 m (0–3000 ft) |
Distribution |
AL; AR; AZ; CA; CO; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; MI; MO; MS; MT; NC; ND; NE; NJ; NM; NV; NY; OH; OK; OR; PA; SC; TN; TX; UT; VA; WA; WV; WY; AB; BC; MB; NT; ON; QC; SK
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AL; AR; FL; GA; IL; IN; KY; LA; MA; MD; MI; MO; MS; NC; NJ; OH; OK; PA; SC; TN; TX; VA; WI; WV; NS; ON; QC
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Discussion | It has been suggested that Helenium flexuosum may be of hybrid origin from H. campestre (perennial, 2n = 28) and some member of Helenium sect. Tetrodus (H. F. L. Rock 1957). The only member of sect. Tetrodus that has a chromosome number of 2n = 28 is H. linifolium, an annual from southern Texas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 21, p. 431. | FNA vol. 21, p. 429. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | H. autumnale var. canaliculatum, H. autumnale var. fylesii, H. autumnale var. grandiflorum, H. autumnale var. montanum, H. autumnale var. parviflorum, H. latifolium, H. parviflorum | H. nudiflorum |
Name authority | Linnaeus: Sp. Pl. 2: 886. (1753) | Rafinesque: New Fl. 4: 81. (1838) |
Web links |
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