The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

common sunflower, hairy leaf sunflower, sunflower

neglected sunflower

Habit Annuals, 100–300 cm. Annuals, 80–200 cm.
Stems

erect, usually hispid.

erect (leafy), ± hispid to glabrate.

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.

cauline; alternate;

petioles 7–12 cm;

blades deltate-ovate, 7–14 × 7.5–12.3 cm, bases usually ± cordate, sometimes truncate, margins subentire to serrulate, abaxial faces strigose, not gland-dotted.

Peduncles

2–20 cm.

10–40 cm.

Involucres

hemispheric or broader, 15–40(–200+) mm diam.

± hemispheric, (23–28 ×) 10–14 mm.

Ray florets

(13–)17–30(–100+);

laminae 25–50 mm.

21–31;

laminae 29–39 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).

150+;

corollas 6–6.5 mm, lobes reddish;

anthers dark, appendages purplish (style branches reddish).

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.

25–35, lanceolate, 14–25 × 2.3–4 mm (surpassing discs), apices long-attenuate, abaxial faces strigillose to hispid.

Heads

1–9.

1–5.

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.

4–5 mm, strigillose to glabrate;

pappi of 2 aristate scales 2.8–3.2 mm.

Paleae

9–11 mm, 3-toothed (middle teeth long-acuminate, glabrous or hispid).

9–10 mm, 3-toothed (middle teeth ± ciliate or bearded, hairs whitish, 0.3–0.6 mm).

2n

= 34.

= 34.

Helianthus annuus

Helianthus neglectus

Phenology Flowering summer–fall. Flowering summer–fall.
Habitat Open areas Sandy soils, sand dunes
Elevation 0–3000 m (0–9800 ft) 800–1100 m (2600–3600 ft)
Distribution
from FNA
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
[WildflowerSearch map]
[BONAP county map]
from FNA
NM; TX
[BONAP county map]
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.)

Of conservation concern.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 21, p. 149. FNA vol. 21, p. 153.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Helianthinae > Helianthus Asteraceae > tribe Heliantheae > subtribe Helianthinae > Helianthus
Sibling taxa
H. agrestis, H. angustifolius, 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. divaricatus, 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
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. divaricatus, 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. 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. 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
Name authority Linnaeus: Sp. Pl. 2: 904. (1753) Heiser: Rhodora 60: 275, fig. 2. (1958)
Web links