Vernonia arkansana |
Vernonia lettermannii |
|
---|---|---|
Arkansas ironweed, great ironweed |
narrowleaf ironweed, slimleaf ironweed |
|
Habit | Plants 8–12(–20) dm. | Plants (2–)5–6+ dm. |
Stems | scabrellous to pilosulous, glabrescent. |
glabrous or glabrate. |
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 filiform, 5–9+ cm × 1–3+ mm, l/w = 25–50+, abaxially glabrate (pitted, awl-shaped hairs in pits), adaxially puberulent, glabrescent (sometimes pitted). |
Peduncles | 2–5 cm. |
6–20+ mm. |
Involucres | ± hemispheric, 11–15 × 11–15 mm. |
narrowly campanulate, 7–9(–10+) × 4–5+ mm. |
Florets | 50–100+. |
10–12+. |
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. |
30–40+ 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. |
Heads | in ± corymbiform arrays. |
in corymbiform 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. |
3–4 mm; pappi fuscous to purplish, outer scales 25+, 0.1–0.5 mm, contrasting with 35+, 6–7+ mm inner bristles. |
2n | = 34. |
= 34. |
Vernonia arkansana |
Vernonia lettermannii |
|
Phenology | Flowering Aug–Oct. | Flowering Jul–Aug. |
Habitat | Leas, roadsides, stream banks, in sand or on limestone | Flood plains, terraces |
Elevation | 200–300 m (700–1000 ft) | 100–200 m (300–700 ft) |
Distribution |
AR; KS; MO; OK
|
AR; OK
|
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. 211. |
Parent taxa | Asteraceae > tribe Vernonieae > Vernonia | Asteraceae > tribe Vernonieae > Vernonia |
Sibling taxa | ||
Synonyms | V. crinita | |
Name authority | de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 7: 264. (1838) | Engelmann ex A. Gray: Notes Compositae, 78. (1880) |
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