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prairie ironweed, smooth ironweed, western ironweed

Baldwin's ironweed

Habit Plants 3–12+ dm. Plants 6–10(–15) dm.
Stems

puberulent, glabrescent.

puberulent to ± tomentose.

Leaves

mostly cauline;

blades ± lanceolate, 5–12(–20+) cm × 5–18(–40+) mm, l/w = 5–9(–14+), abaxially glabrate (pitted, with awl-shaped hairs in pits), adaxially scabrellous, resin-gland-dotted (sometimes pitted).

mostly cauline;

blades elliptic to lance-ovate or lanceolate, 8–15(–18+) cm × 20–45(–75+) mm, l/w = 2–5, abaxially usually puberulent to tomentose or pannose (hairs ± erect, ± curled), seldom glabrate, resin-gland-dotted, adaxially scabrellous, glabrescent, not resin-gland-dotted.

Peduncles

1–8(–12+) mm.

1–25 mm.

Involucres

± campanulate, 5–7(–8+) × 4–6 mm.

broadly campanulate to hemispheric, 4–6(–8+) × 4–7+ mm.

Florets

12–25+.

(15–)20–25(–35+).

Phyllaries

25–35+ in 4–5+ series, glabrescent, margins arachno-ciliolate, the outer lance-ovate, 1–3 mm, inner oblong to linear-oblong, 5–7+ mm, tips acute or rounded-apiculate.

45–65+ in 5–6 series, usually puberulent (often resin-gland-dotted distally), sometimes glabrescent, margins ciliolate, the outer lance-ovate, 1–2 mm, inner oblong to lanceolate, 5–8+ mm, tips rounded-apiculate to acute (sometimes recurved).

Heads

in congested, corymbiform arrays.

in corymbiform-scorpioid arrays.

Cypselae

3.5–4 mm;

pappi fuscous to purplish, outer subulate scales or bristles 20–30, 0.5–3+ mm, intergrading with 35–45+, 5–7+ mm inner subulate scales or bristles.

2.5–3 mm;

pappi fuscous to purplish, outer scales 25–30, 0.2–1 mm, contrasting with 35–40+, 5–7+ mm inner bristles.

2n

= 34.

= 34.

Vernonia fasciculata

Vernonia baldwinii

Phenology Flowering Jul–Sep. Flowering Jun–Nov.
Habitat Bottomlands, ditches, low prairies Disturbed places, grasslands, flood plains, forest margins, prairies
Elevation 100–1200 m (300–3900 ft) 10–1100 m (0–3600 ft)
Distribution
from FNA
CO; IA; IL; IN; KS; KY; MA; MN; MO; ND; NE; OH; OK; SD; WI; MB
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; CO; IA; IL; KS; KY; LA; MI; MO; NE; OK; TX
[WildflowerSearch map]
[BONAP county map]
Discussion

Regarding Vernona baldwinii and V. interior, L. H. Shinners (1950) wrote, “The tips of the phyllaries vary from loosely appressed to squarrose, and from puberulent to almost completely glabrous on the inner face. The geographic distribution of the two extremes is nearly identical. I consider the two to be merely forms of one species.” I concur.

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

Source FNA vol. 19, p. 211. FNA vol. 19, p. 213.
Parent taxa Asteraceae > tribe Vernonieae > Vernonia Asteraceae > tribe Vernonieae > Vernonia
Sibling taxa
V. acaulis, V. angustifolia, V. arkansana, V. baldwinii, V. blodgettii, 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. 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. fasciculata subsp. corymbosa, V. fasciculata var. corymbosa V. baldwinii subsp. interior, V. baldwinii var. interior, V. interior
Name authority Michaux: Fl. Bor.-Amer. 2: 94. (1803) Torrey: Ann. Lyceum Nat. Hist. New York 2: 211. (1827)
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