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woodland sunflower

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

Phenology Flowering summer–early fall.
Habitat Dry, open sites
Elevation 10–900+ m (0–3000+ ft)
Distribution
from FNA
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
H. agrestis, H. angustifolius, H. annuus, H. anomalus, H. argophyllus, H. arizonensis, H. atrorubens, H. bolanderi, H. californicus, H. carnosus, H. ciliaris, H. cusickii, H. debilis, H. decapetalus, H. deserticola, H. eggertii, H. exilis, H. floridanus, H. giganteus, H. glaucophyllus, H. gracilentus, H. grosseserratus, H. heterophyllus, H. hirsutus, H. laciniatus, H. laevigatus, H. longifolius, H. maximiliani, H. microcephalus, H. mollis, H. neglectus, H. niveus, H. nuttallii, H. occidentalis, H. paradoxus, H. pauciflorus, H. petiolaris, H. porteri, H. praecox, H. pumilus, H. radula, H. resinosus, H. salicifolius, H. schweinitzii, H. silphioides, H. simulans, H. smithii, H. strumosus, H. tuberosus, H. verticillatus, H. ×laetiflorus
Synonyms H. divaricatus var. angustifolius
Name authority Linnaeus: Sp. Pl. 2: 906. (1753)
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