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tall ironweed

Arkansas ironweed, great ironweed

Habit Plants 5–10+ dm. Plants 8–12(–20) dm.
Stems

sparsely appressed-puberulent, glabrescent.

scabrellous to pilosulous, glabrescent.

Leaves

mostly cauline;

blades (mid stem) lance-linear to filiform, 5–12 cm × 2–4(–8+) mm, l/w = (8–)12–30(–60+), abaxially glabrous but for scattered hairs on midribs or scabrellous (hairs awl-shaped), resin-gland-dotted or not, adaxially scabrellous.

mostly cauline;

blades lance-linear, 6–14(–20) cm × 7–15(–25) mm, l/w = 7–10(–18), abaxially scabrellous (hairs awl-shaped), resin-gland-dotted, adaxially scaberulous, glabrescent, resin-gland-dotted.

Peduncles

8–25 mm.

2–5 cm.

Involucres

± campanulate to obconic, 5–7(–10) × 4–6(–9) mm.

± hemispheric, 11–15 × 11–15 mm.

Florets

12–20(–30).

50–100+.

Phyllaries

22–45+ in 5–6 series, sparsely scabrellous, glabrescent, margins ciliolate, the outer lanceolate to subulate, 1.5–3 mm, inner lance-ovate to lanceolate, 5–9+ mm, tips acuminate to subulate.

(50–)60–70+ in 5–6 series, scabrellous (and resin-gland-dotted), margins ciliolate, the outer lance-ovate, 3–8+ mm, inner lanceolate, 12–15 mm, tips subulate to filiform.

Heads

in ± corymbiform to paniculiform arrays.

in ± corymbiform arrays.

Cypselae

2.5–3 mm;

pappi stramineous to purplish, outer scales 25–30, 0.5–1.2+ mm, contrasting with 35–40+, 5.5–6+ mm inner bristles.

3–5 mm;

pappi fuscous to purplish, outer scales 25–30+, 0.5–1 mm, contrasting with 25–30+, 5–7 mm inner bristles.

2n

= 34.

= 34.

Vernonia angustifolia

Vernonia arkansana

Phenology Flowering Jun–Aug. Flowering Aug–Oct.
Habitat Pine barrens, oak woodlands Leas, roadsides, stream banks, in sand or on limestone
Elevation 10–50 m (0–200 ft) 200–300 m (700–1000 ft)
Distribution
from FNA
AL; FL; GA; LA; MS; NC; SC
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; KS; MO; OK
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[BONAP county map]
Discussion

Vernonia arkansana was published in April, V. crinita in October 1838.

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

Source FNA vol. 19, p. 209. FNA vol. 19, p. 208.
Parent taxa Asteraceae > tribe Vernonieae > Vernonia Asteraceae > tribe Vernonieae > Vernonia
Sibling taxa
V. acaulis, V. arkansana, V. baldwinii, V. blodgettii, V. fasciculata, V. flaccidifolia, V. gigantea, V. glauca, V. larseniae, V. lettermannii, V. lindheimeri, V. marginata, V. missurica, V. noveboracensis, V. pulchella, V. texana
V. acaulis, V. angustifolia, V. baldwinii, V. blodgettii, V. fasciculata, V. flaccidifolia, V. gigantea, V. glauca, V. larseniae, V. lettermannii, V. lindheimeri, V. marginata, V. missurica, V. noveboracensis, V. pulchella, V. texana
Synonyms V. angustifolia subsp. mohrii, V. angustifolia subsp. scaberrima, V. angustifolia var. scaberrima, V. scaberrima V. crinita
Name authority Michaux: Fl. Bor.-Amer. 2: 94. (1803) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 7: 264. (1838)
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