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girasole, Jerusalem artichoke, Jerusalem sunflower, topinambour, tuberous sunflower

lakeside sunflower

Habit Perennials, 50–200+ cm (rhizomatous, producing tubers late in growing season). Perennials, 10–60 cm, (with crown buds).
Stems

erect, scabro-hispid to hirsute (sometimes glaucous).

erect, (unbranched) glabrous, eglandular.

Leaves

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).

mostly basal; opposite (proximal) or alternate;

petioles obscure (intergrading with blades);

blades lanceolate to lance-linear or linear, 10–25 × 0.5–1.5 cm, bases cuneate, margins entire, faces glabrous, not gland-dotted (cauline 1–5 pairs, smaller).

Peduncles

1–15 cm.

5–10 cm.

Involucres

hemispheric, (10–25 ×) 8–12 mm.

broadly hemispheric, 17–25 mm diam.

Ray florets

10–20;

laminae 25–40 mm.

12–17;

laminae 20–40 mm, (abaxial faces not gland-dotted).

Disc florets

60+;

corollas 6–7 mm, lobes yellow;

anthers dark brown or black, appendages dark or yellowish.

100+;

corollas 6–6.5 mm, lobes yellow;

anthers dark, appendages yellowish or dark.

Phyllaries

(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.

(green with purple veins) 25–30, ovate to lance-ovate, 8–16 × 3–5 mm, apices acuminate, abaxial faces usually glabrous, sometimes puberulent.

Heads

3–15.

1(–3).

Cypselae

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.

3 mm, glabrous;

pappi of 2 aristate scales 1.5–2 mm plus 2–4 erose scales 0.3–0.6 mm.

Paleae

8–9 mm, 3-toothed (apices hairy).

8–9 mm, 3-toothed (middle teeth long-acuminate).

2n

= 102.

= 34.

Helianthus tuberosus

Helianthus carnosus

Phenology Flowering late summer–fall. Flowering early–late summer.
Habitat Roadsides, fields, waste areas Wet prairies, flatwoods
Elevation 0–1000(–1500) m (0–3300(–4900) ft) 0–10+ m (0–0+ ft)
Distribution
from FNA
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
[WildflowerSearch map]
[BONAP county map]
from FNA
FL
[BONAP county map]
Discussion

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.)

Of conservation concern.

Helianthus carnosus is distinctive in morphology and is known from relatively few counties in northeastern Florida.

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

Source FNA vol. 21, p. 161. FNA vol. 21, p. 156.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Helianthinae > Helianthus 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. 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. verticillatus, H. ×laetiflorus
H. agrestis, H. angustifolius, H. annuus, H. anomalus, H. argophyllus, H. arizonensis, H. atrorubens, H. bolanderi, H. californicus, 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
Synonyms H. tomentosus, H. tuberosus var. subcanescens
Name authority Linnaeus: Sp. Pl. 2: 905. (1753) Small: Torreya 2: 74. (1902)
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