Vernonia acaulis |
Vernonia arkansana |
|
---|---|---|
stemless ironweed |
Arkansas ironweed, great ironweed |
|
Habit | Plants 4–6(–10) dm. | Plants 8–12(–20) dm. |
Stems | ± puberulent, glabrescent. |
scabrellous to pilosulous, glabrescent. |
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 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. |
Peduncles | 5–50 mm. |
2–5 cm. |
Involucres | campanulate to hemispheric, 5–10 × 6–7 mm. |
± hemispheric, 11–15 × 11–15 mm. |
Florets | 30–40(–55+). |
50–100+. |
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. |
(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. |
Heads | in loose, corymbiform arrays. |
in ± corymbiform 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. |
3–5 mm; pappi fuscous to purplish, outer scales 25–30+, 0.5–1 mm, contrasting with 25–30+, 5–7 mm inner bristles. |
2n | = 34. |
= 34. |
Vernonia acaulis |
Vernonia arkansana |
|
Phenology | Flowering Jul–Aug. | Flowering Aug–Oct. |
Habitat | Open woods, pine savannas, bogs, disturbed places | Leas, roadsides, stream banks, in sand or on limestone |
Elevation | 10–300 m (0–1000 ft) | 200–300 m (700–1000 ft) |
Distribution |
FL; GA; NC; SC
|
AR; KS; MO; 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. 208. |
Parent taxa | Asteraceae > tribe Vernonieae > Vernonia | Asteraceae > tribe Vernonieae > Vernonia |
Sibling taxa | ||
Synonyms | Chrysocoma acaulis | V. crinita |
Name authority | (Walter) Gleason: Bull. New York Bot. Gard. 4: 222. (1906) | de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 7: 264. (1838) |
Web links |