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Helenium autumnale

common sneezeweed, fall sneezeweed, hélénie automnale, large-flower sneezeweed, mountain sneezeweed

hélénie nudiflore, purple sneezeweed, purple-head sneezeweed

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

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
from FNA
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
[WildflowerSearch map]
[BONAP county map]
from FNA
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
[WildflowerSearch map]
[BONAP county map]
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.)

Source FNA vol. 21, p. 431. FNA vol. 21, p. 429.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Gaillardiinae > Helenium Asteraceae > tribe Heliantheae > subtribe Gaillardiinae > Helenium
Sibling taxa
H. amarum, H. arizonicum, H. bigelovii, H. bolanderi, H. brevifolium, H. campestre, H. drummondii, H. elegans, H. flexuosum, H. linifolium, H. microcephalum, H. pinnatifidum, H. puberulum, H. quadridentatum, H. thurberi, H. vernale, H. virginicum
H. amarum, H. arizonicum, H. autumnale, H. bigelovii, H. bolanderi, H. brevifolium, H. campestre, H. drummondii, H. elegans, H. linifolium, H. microcephalum, H. pinnatifidum, H. puberulum, H. quadridentatum, H. thurberi, H. vernale, H. virginicum
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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