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Arkansas ironweed, great ironweed

Tennessee ironweed

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

scabrellous to pilosulous, glabrescent.

glabrous.

Leaves

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.

mostly cauline;

blades ± lanceolate, 10–25(–30+) cm × 15–35(–60+) mm, l/w = 5–7+, abaxially puberulous, not resin-gland-dotted, adaxially scabrellous, glabrescent, not resin-gland-dotted.

Peduncles

2–5 cm.

1–8(–15) mm.

Involucres

± hemispheric, 11–15 × 11–15 mm.

broadly campanulate to hemispheric, 4–5+ × 4–5 mm.

Florets

50–100+.

15–25+.

Phyllaries

(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.

30–45+ in 5–6 series, glabrescent, margins ciliolate, the outer lance-ovate, 1–3 mm, inner lance-oblong to oblong, 3.5–5 mm, tips rounded.

Heads

in ± corymbiform arrays.

in paniculiform-scorpioid arrays.

Cypselae

3–5 mm;

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

3–3.5 mm;

pappi stramineous to whitish, outer scales 25–35, 0.8–1.1 mm, contrasting with 35–45+, 5–6+ mm inner bristles.

2n

= 34.

= 34.

Vernonia arkansana

Vernonia flaccidifolia

Phenology Flowering Aug–Oct. Flowering Aug.
Habitat Leas, roadsides, stream banks, in sand or on limestone Disturbed places in woodlands
Elevation 200–300 m (700–1000 ft) 90–400 m (300–1300 ft)
Distribution
from FNA
AR; KS; MO; OK
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; GA; TN
[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. 208. FNA vol. 19, p. 212.
Parent taxa Asteraceae > tribe Vernonieae > Vernonia Asteraceae > tribe Vernonieae > Vernonia
Sibling taxa
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
V. acaulis, V. angustifolia, V. arkansana, V. baldwinii, V. blodgettii, V. fasciculata, V. gigantea, V. glauca, V. larseniae, V. lettermannii, V. lindheimeri, V. marginata, V. missurica, V. noveboracensis, V. pulchella, V. texana
Synonyms V. crinita
Name authority de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 7: 264. (1838) Small: Bull. Torrey Bot. Club 25: 144. (1898)
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