Contains 26 accepted taxa overall.
Characteristics
Classification
Citation
HELIANTHUS Linnaeus, Sp. Pl. 904. 1753.
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TYPE: Helianthus annuus Linnaeus Lectotypified by Britton & A. Brown, Ill. Fl. N. U.S., ed. 2. 3: 477. 1913.
Species
| Scientific Name | Common Name | Herbarium Specimens | Status | Photos |
|---|---|---|---|---|
| Helianthus angustifolius | Narrowleaf Sunflower | |||
| Helianthus annuus | Common Sunflower | |||
| Helianthus atrorubens | Appalachian Sunflower | |||
| Helianthus debilis ssp. cucumerifolius | Cucumber-leaf Sunflower | |||
| Helianthus decapetalus | Forest Sunflower | |||
| Helianthus divaricatus | Spreading Sunflower | |||
| Helianthus eggertii | Eggert's Sunflower | |||
| Helianthus floridanus | Florida Sunflower | |||
| Helianthus giganteus | Tuberous Sunflower, Swamp Sunflower | |||
| Helianthus glaucophyllus | Whiteleaf Sunflower | |||
| Helianthus heterophyllus | Savanna Sunflower | |||
| Helianthus hirsutus | Hairy Sunflower | |||
| Helianthus laetiflorus | Showy Sunflower | |||
| Helianthus laevigatus | Shale-barren Sunflower, Smooth Sunflower | |||
| Helianthus maximilianii | Maximilian Sunflower | |||
| Helianthus microcephalus | Small-headed Sunflower | |||
| Helianthus mollis | Ashy Sunflower, Gray Sunflower | |||
| Helianthus occidentalis ssp. occidentalis | ||||
| Helianthus petiolaris ssp. petiolaris | Plains Sunflower | |||
| Helianthus porteri | Confederate Daisy | |||
| Helianthus radula | Roundleaf Sunflower, Rayless Sunflower | |||
| Helianthus resinosus | Resinous Sunflower | |||
| Helianthus schweinitzii | Schweinitz's Sunflower | |||
| Helianthus simulans | Muck Sunflower | |||
| Helianthus strumosus | Roughleaf Sunflower | |||
| Helianthus tuberosus | Jerusalem Artichoke |
Identification Key
1. Plant subscapose, the basal leaves persistent, up to 4 nodes of cauline leaves; leaves not glandular-punctate; heads 1-4(12)
2
1. Plant leafy throughout, the basal leaves often withering, leafy cauline nodes numerous; leaves sometimes glandular-punctate; heads 1-
5
2. Stems (and leaves) usually glabrous; disc corolla lobes yellow
2. Stems (and leaves) usually hispid or hirsute to scabrous; disc corolla lobes yellow or reddish
3
3. Ray florets 0 or 2–8, laminae 1–2(–10) mm (inconspicuous, often tinged reddish)
3. Ray florets 8–13(–25), laminae (7–)10–40 mm (yellow)
4
4. Phyllaries lanceolate to ovate (the larger 3+ mm wide); abaxial faces usually not gland-dotted (if gland-dotted, cypselae 5–6 mm); disc corolla lobes reddish or yellow
4. Phyllaries lanceolate (the larger 1.5–2.5 mm wide); abaxial faces of leaves (and usually ray laminae) notably gland-dotted; disc corolla lobes yellow; cypselae 3–5 mm
5. Leaves 0.2-1.1(1.7) cm wide
5. Leaves 1.1-40 cm wide
6
6. Disc corollas reddish or purplish
7
6. Disc corollas yellow
15
7. Stems (leaves, phyllaries) densely silvery white tomentose or floccose
7. Stems (leaves, phyllaries) hispid to glabrate
8
8. Petioles 0-1.2 cm long; leaf blades 4-12 times longer than wide
9
8. Petioles 1-10+ cm long (at least of larger leaves, petiole sometimes winged from decurrent leaf bases); leaf blades 1.3-3(4) times longer than wide
11
9. Annual; leaves not glandular-punctate; phyllaries 15-25, eglandular
9. Perennial, rhizomatous; leaves glandular-punctate; phyllaries 25-38, glandular-punctate
10
10. Leaf blade margins usually undulate and revolute
10. Leaf blade margins not undulate, not or only slightly revolute
11. Phyllaries oblong, ovate, to lance-ovate
12
11. Phyllaries lanceolate
13
12. Leaves primarily alternate, blade base mostly shortly cuneate to subtruncate; involucre 15-200+ mm wide
12. Leaves primarily opposite, blade base decurrent along the petiole; involucre 9-16 mm wide
13. Stem erect, hispid, usually red-brown mottled; peduncles 25-50 cm long
13. Stem decumbent, glabrous to hispid or hirsute; peduncles 9-20(22) cm long
14
14. Stems glabrous to puberulent; leaf blades serrulate or shallowly, regularly serrate, lower surface sparsely, if at all, glandular-punctate
14. Stems hirsute; leaf blades deeply, irregularly serrate, lower surface densely glandular-punctate
15. Tuber-bearing and rhizomatous; petioles 2-8 cm long
15. Rhizomatous or not, without tubers; petioles 0-3 cm long
16
16. Phyllaries glandular-punctate, usually squarrose to reflexed; leaf blade bases
16. Phyllaries eglandular, appressed, ascending, to loosely spreading
17
17. Petioles 0-1.2 cm long
18
17. Petioles (0.5)1-3 cm long
20
18. Stem glabrous to glabrate; leaf blade base often subcordate, often partly overlapping with the stem
18. Stem hispid; leaf blade base cuneate, not overlapping with the stem
19
19. Leaf blade margins usually undulate and revolute
19. Leaf blade margins not undulate, not or only slightly revolute
20. Stem hirsute
20. Stem glabrous to glabrate
21
21. Lacking rhizomes; involucre 5-7 mm wide; ray flowers 5-8; disc flowers 15-22
21. Rhizomatous; involucre 8-20 mm wide; ray flowers 10-20; disc flowers 30-60
Genus Synonyms
| Synonym | Full Citation | Basionym | Type |
|---|---|---|---|
| No synonyms found. | |||