Helianthus annuus |
Helianthus tuberosus |
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common sunflower, hairy leaf sunflower, sunflower |
girasole, Jerusalem artichoke, Jerusalem sunflower, topinambour, tuberous sunflower |
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Habit | Annuals, 100–300 cm. | Perennials, 50–200+ cm (rhizomatous, producing tubers late in growing season). |
Stems | erect, usually hispid. |
erect, scabro-hispid to hirsute (sometimes glaucous). |
Leaves | mostly cauline; mostly alternate; petioles 2–20 cm; blades lance-ovate to ovate, 10–40 × 5–40 cm, bases cuneate to subcordate or cordate, margins serrate, abaxial faces usually ± hispid, sometimes gland-dotted. |
mostly cauline; opposite or alternate proximally, usually alternate distally; petioles 2–8 cm (often ± winged); blades (3-nerved from near bases) lanceolate to ovate, 10–23 × 7–15 cm, bases broadly to narrowly cuneate, margins entire or serrate (flat), abaxial faces puberulent or hirsutulous to tomentulose and gland-dotted (abaxial) or ± scabrous (adaxial). |
Peduncles | 2–20 cm. |
1–15 cm. |
Involucres | hemispheric or broader, 15–40(–200+) mm diam. |
hemispheric, (10–25 ×) 8–12 mm. |
Ray florets | (13–)17–30(–100+); laminae 25–50 mm. |
10–20; laminae 25–40 mm. |
Disc florets | 150+(–1000+); corollas 5–8 mm (throats ± bulbous at bases), lobes usually reddish, sometimes yellow; anthers brownish to black, appendages yellow or dark (style branches yellow). |
60+; corollas 6–7 mm, lobes yellow; anthers dark brown or black, appendages dark or yellowish. |
Phyllaries | 20–30(–100+), ovate to lance-ovate, 13–25 × (3–)5–8 mm, (margins usually ciliate) apices abruptly narrowed, long-acuminate, abaxial faces usually hirsute to hispid, rarely glabrate or glabrous, usually gland-dotted. |
(often dark green, drying nearly black) 22–35 (bases appressed, apices ± spreading, sometimes reflexed in fruit), lanceolate, 8.5–15 × 2–4 mm (subequal), (margins ciliate) apices acuminate, abaxial faces hispidulous or puberulent, gland-dotted. |
Heads | 1–9. |
3–15. |
Cypselae | (3–)4–5(–15) mm, glabrate; pappi of 2 lanceolate scales 2–3.5 mm plus 0–4 obtuse scales 0.5–1 mm. |
5–7 mm, glabrous or distally hairy; pappi of 2 aristate scales 1.9–3 mm plus 0–1 deltate scales 0.5–0.8 mm. |
Paleae | 9–11 mm, 3-toothed (middle teeth long-acuminate, glabrous or hispid). |
8–9 mm, 3-toothed (apices hairy). |
2n | = 34. |
= 102. |
Helianthus annuus |
Helianthus tuberosus |
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Phenology | Flowering summer–fall. | Flowering late summer–fall. |
Habitat | Open areas | Roadsides, fields, waste areas |
Elevation | 0–3000 m [0–9800 ft] | 0–1000(–1500) m [0–3300(–4900) ft] |
Distribution |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; NT; ON; PE; QC; SK; SPM; Mexico; intoduced nearly worldwide
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AL; AR; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; MB; NB; NS; ON; PE; QC; SK; cultivated and adventive in Europe
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Discussion | Helianthus annuus is widely distributed, including weedy, cultivated, and escaped plants. It is the only native North American species to become a major agronomic crop. Despite its considerable variability, attempts have failed to produce a widely adopted infraspecific system of classification. Forms with red-colored ray laminae, known from cultivation and occasionally seen escaped, trace their ancestry to a single original mutant plant. It hybridizes with many of the other annual species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Helianthus tuberosus is variable, probably in part stemming from hybridization with other polyploids, including H. pauciflorus, H. resinosus, and H. strumosus. Helianthus tuberosus is so widely spread as a weedy species that its original distribution is difficult to discern. It has been used as a food plant for its tubers by native Americans (although not necessarily domesticated or even cultivated); it has been developed as a crop primarily in Europe, where it has become widely naturalized. The common name Jerusalem artichoke is a misnomer, as explained by C. B. Heiser (1976). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 149. | FNA vol. 21, p. 161. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | H. annuus subsp. jaegeri, H. annuus subsp. lenticularis, H. annuus var. lenticularis, H. annuus var. macrocarpus, H. annuus subsp. texanus, H. aridus, H. jaegeri, H. lenticularis, H. macrocarpus | H. tomentosus, H. tuberosus var. subcanescens |
Name authority | Linnaeus: Sp. Pl. 2: 904. (1753) | Linnaeus: Sp. Pl. 2: 905. (1753) |
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