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narrowleaf ironweed, slimleaf ironweed

giant ironweed, tall ironweed

Habit Plants (2–)5–6+ dm. Plants 8–20(–30+) dm.
Stems

glabrous or glabrate.

puberulent, glabrescent.

Leaves

mostly cauline;

blades filiform, 5–9+ cm × 1–3+ mm, l/w = 25–50+, abaxially glabrate (pitted, awl-shaped hairs in pits), adaxially puberulent, glabrescent (sometimes pitted).

mostly cauline;

blades ± lanceolate, 12–25+ cm × 20–60+ mm, l/w = (3.5–)4–7+, abaxially scabrellous (hairs awl-shaped), sometimes glabrescent, not or sparsely resin-gland-dotted, adaxially strigillose, glabrescent, not resin-gland-dotted.

Peduncles

6–20+ mm.

1–12(–20+) mm.

Involucres

narrowly campanulate, 7–9(–10+) × 4–5+ mm.

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

Florets

10–12+.

(9–)18–24(–30).

Phyllaries

30–40+ in 5–6+ series, sparsely tomentose, glabrescent, margins arachno-ciliolate, the outer lanceolate to subulate, 1–3 mm, inner oblong to lanceolate, 5–7+ mm, tips acute.

30–40+ in 4–5 series, glabrate, margins ciliolate, the outer lance-ovate, 1–2 mm, inner oblong, 3.5–5 mm, tips acute or rounded-apiculate.

Heads

in corymbiform arrays.

in corymbiform-scorpioid arrays.

Cypselae

3–4 mm;

pappi fuscous to purplish, outer scales 25+, 0.1–0.5 mm, contrasting with 35+, 6–7+ mm inner bristles.

2.5–3.5 mm;

pappi usually purplish, sometimes stramineous, outer scales 20–25, 0.5–1 mm, contrasting with 35–40+, 4.5–6+ mm inner bristles.

2n

= 34.

= 34.

Vernonia lettermannii

Vernonia gigantea

Phenology Flowering Jul–Aug. Flowering Jun–Sep.
Habitat Flood plains, terraces Flood plains
Elevation 100–200 m (300–700 ft) 10–300 m (0–1000 ft)
Distribution
from FNA
AR; OK
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; FL; GA; IL; IN; KS; KY; LA; MD; MI; MO; MS; NC; NE; OH; OK; PA; SC; TN; TX; VA; WV; ON
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 19, p. 211. FNA vol. 19, p. 212.
Parent taxa Asteraceae > tribe Vernonieae > Vernonia Asteraceae > tribe Vernonieae > Vernonia
Sibling taxa
V. acaulis, V. angustifolia, V. arkansana, V. baldwinii, V. blodgettii, V. fasciculata, V. flaccidifolia, V. gigantea, V. glauca, V. larseniae, 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. glauca, V. larseniae, V. lettermannii, V. lindheimeri, V. marginata, V. missurica, V. noveboracensis, V. pulchella, V. texana
Synonyms Chrysocoma gigantea, V. altissima, V. altissima var. taeniotricha, V. gigantea subsp. ovalifolia, V. ovalifolia
Name authority Engelmann ex A. Gray: Notes Compositae, 78. (1880) (Walter) Branner & Coville: Rep. (Annual) Arkansas Geol. Surv. 4: 189. (1891)
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