Vernonia arkansana |
Vernonia gigantea |
|
---|---|---|
Arkansas ironweed, great ironweed |
giant ironweed, tall ironweed |
|
Habit | Plants 8–12(–20) dm. | Plants 8–20(–30+) dm. |
Stems | scabrellous to pilosulous, glabrescent. |
puberulent, glabrescent. |
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 ± 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 | 2–5 cm. |
1–12(–20+) mm. |
Involucres | ± hemispheric, 11–15 × 11–15 mm. |
broadly campanulate to hemispheric, 4–5+ × 4–5 mm. |
Florets | 50–100+. |
(9–)18–24(–30). |
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 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 | 3–5 mm; pappi fuscous to purplish, outer scales 25–30+, 0.5–1 mm, contrasting with 25–30+, 5–7 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 arkansana |
Vernonia gigantea |
|
Phenology | Flowering Aug–Oct. | Flowering Jun–Sep. |
Habitat | Leas, roadsides, stream banks, in sand or on limestone | Flood plains |
Elevation | 200–300 m (700–1000 ft) | 10–300 m (0–1000 ft) |
Distribution |
AR; KS; MO; OK
|
AL; AR; FL; GA; IL; IN; KS; KY; LA; MD; MI; MO; MS; NC; NE; OH; OK; PA; SC; TN; TX; VA; WV; ON
|
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 | ||
Synonyms | V. crinita | Chrysocoma gigantea, V. altissima, V. altissima var. taeniotricha, V. gigantea subsp. ovalifolia, V. ovalifolia |
Name authority | de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 7: 264. (1838) | (Walter) Branner & Coville: Rep. (Annual) Arkansas Geol. Surv. 4: 189. (1891) |
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