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Arkansas ironweed, great ironweed

Missouri ironweed

Habit Plants 8–12(–20) dm. Plants 6–12(–20+) dm.
Stems

scabrellous to pilosulous, glabrescent.

puberulent.

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 elliptic to lance-ovate or lanceolate, 6–16(–20+) cm × 18–48+ mm, l/w = 2.5–4(–6+), abaxially usually puberulent to tomentose or pannose (hairs ± erect, ± curled), seldom glabrate, resin-gland-dotted, adaxially scabrellous, glabrescent, not resin-gland-dotted.

Peduncles

2–5 cm.

3–35 mm.

Involucres

± hemispheric, 11–15 × 11–15 mm.

broadly campanulate to urceolate, (6–)7–10+ × 5–9+ mm.

Florets

50–100+.

30–55+.

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.

50–70+ in 6–7 series, sparsely scabrellous, glabrescent (seldom resin-gland-dotted), margins ciliolate, the outer lanceolate, 1–2 mm, inner linear-oblong to oblong, 6–7(–9+) mm, tips acute or rounded-apiculate.

Heads

in ± corymbiform arrays.

in corymbiform-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.

3.5–4;

pappi stramineous to whitish, outer scales 25–30, 0.5–1.1 mm, contrasting with 35–40+, 6–8+ mm inner bristles.

2n

= 34.

= 34.

Vernonia arkansana

Vernonia missurica

Phenology Flowering Aug–Oct. Flowering Jul–Sep.
Habitat Leas, roadsides, stream banks, in sand or on limestone Prairies, loamy to sandy soils
Elevation 200–300 m (700–1000 ft) 30–200 m (100–700 ft)
Distribution
from FNA
AR; KS; MO; OK
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; GA; IA; IL; IN; KS; KY; LA; MI; MO; MS; OK; TN; TX
[WildflowerSearch map]
[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. flaccidifolia, V. gigantea, V. glauca, V. larseniae, V. lettermannii, V. lindheimeri, V. marginata, 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) Rafinesque: Herb. Raf., 28. (1833)
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