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stemless ironweed

Baldwin's ironweed

Habit Plants 4–6(–10) dm. Plants 6–10(–15) dm.
Stems

± puberulent, glabrescent.

puberulent to ± tomentose.

Leaves

mostly basal;

blades oblong-elliptic to spatulate (basal, the distal narrower), 11–25(–30) cm × (21–)60–75+ mm, l/w = 2–4(–5+), abaxially usually glabrous or glabrate, sometimes hirsutulous on veins, usually resin-gland-dotted, adaxially ± scabrellous or glabrate.

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

5–50 mm.

1–25 mm.

Involucres

campanulate to hemispheric, 5–10 × 6–7 mm.

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

Florets

30–40(–55+).

(15–)20–25(–35+).

Phyllaries

40–60 in 5–6 series, glabrate, margins ciliolate, the outer lance-linear, 2–4 mm, inner lance-ovate to lance-subulate, 5–9 mm, tips subulate to filiform.

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 loose, corymbiform arrays.

in corymbiform-scorpioid arrays.

Cypselae

2.5–3+ mm;

pappi whitish to stramineous, outer scales ca. 20, 0.6–1 mm, contrasting with 25–40, 5–7+ mm inner 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 acaulis

Vernonia baldwinii

Phenology Flowering Jul–Aug. Flowering Jun–Nov.
Habitat Open woods, pine savannas, bogs, disturbed places Disturbed places, grasslands, flood plains, forest margins, prairies
Elevation 10–300 m (0–1000 ft) 10–1100 m (0–3600 ft)
Distribution
from FNA
FL; GA; NC; SC
[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. 208. FNA vol. 19, p. 213.
Parent taxa Asteraceae > tribe Vernonieae > Vernonia Asteraceae > tribe Vernonieae > Vernonia
Sibling taxa
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. 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 Chrysocoma acaulis V. baldwinii subsp. interior, V. baldwinii var. interior, V. interior
Name authority (Walter) Gleason: Bull. New York Bot. Gard. 4: 222. (1906) Torrey: Ann. Lyceum Nat. Hist. New York 2: 211. (1827)
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