Helianthus divaricatus |
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woodland sunflower |
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Habit | Perennials, 20–150 cm (rhizomatous). |
Stems | erect, usually glabrous, rarely ± hairy (often glaucous). |
Leaves | cauline; opposite; sessile; blades (light to dark green, sometimes whitish abaxially, 3-nerved at bases) lanceolate to lance-ovate, 6–15 × 1–5 cm, bases rounded to cordate, margins subentire to serrate, abaxial faces sparsely hispid to hispidulous, gland-dotted. |
Peduncles | 0.5–9 cm. |
Involucres | hemispheric, 10–15 mm diam. |
Ray florets | 8–12; laminae 15–30 mm. |
Disc florets | 40+; corollas 4.2–5.5 mm, lobes yellow; anthers usually dark brown to black, appendages yellow. |
Phyllaries | 18–25, lanceolate, lance-linear, or lance-ovate, 6–12 × 2–2.5 mm, (margins ciliate) apices acuminate to attenuate, abaxial faces hispidulous to glabrate, not gland-dotted. |
Heads | 1–10. |
Cypselae | 3–3.6 mm, glabrate; pappi of 2 aristate scales 2.2–2.5 mm. |
Paleae | 5–8 mm, 3-toothed (apices ciliate). |
2n | = 34. |
Helianthus divaricatus |
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Phenology | Flowering summer–early fall. |
Habitat | Dry, open sites |
Elevation | 10–900+ m (0–3000+ ft) |
Distribution |
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MI; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; VA; VT; WI; WV; ON; QC
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Discussion | One of the earlier flowering perennial Helianthus, H. divaricatus resembles the tetraploid H. hirsutus but differs by its usually glabrous and often glaucous stems, sessile or subsessile leaves, and smaller reproductive organs (disc corollas, paleae, cypselae). Plants from the Ozark region of Arkansas have larger leaves and heads and may represent a polyploid form of H. divaricatus. Natural hybrids with H. microcephalus have been named H. glaucus Small (D. M. Smith and A. T. Guard 1958). Hybrids with other species differ from H. divaricatus in having short but distinct petioles, hairy stems, leaves with more rounded bases, and primary lateral leaf veins diverging in a subopposite manner distal to bases, rather than being strictly opposite and basal. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 157. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Helianthinae > Helianthus |
Sibling taxa | |
Synonyms | H. divaricatus var. angustifolius |
Name authority | Linnaeus: Sp. Pl. 2: 906. (1753) |
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