Vernonia acaulis |
Vernonia fasciculata |
|
---|---|---|
stemless ironweed |
prairie ironweed, smooth ironweed, western ironweed |
|
Habit | Plants 4–6(–10) dm. | Plants 3–12+ dm. |
Stems | ± puberulent, glabrescent. |
puberulent, 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 ± 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). |
Peduncles | 5–50 mm. |
1–8(–12+) mm. |
Involucres | campanulate to hemispheric, 5–10 × 6–7 mm. |
± campanulate, 5–7(–8+) × 4–6 mm. |
Florets | 30–40(–55+). |
12–25+. |
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. |
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. |
Heads | in loose, corymbiform arrays. |
in congested, 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. |
3.5–4 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. |
2n | = 34. |
= 34. |
Vernonia acaulis |
Vernonia fasciculata |
|
Phenology | Flowering Jul–Aug. | Flowering Jul–Sep. |
Habitat | Open woods, pine savannas, bogs, disturbed places | Bottomlands, ditches, low prairies |
Elevation | 10–300 m (0–1000 ft) | 100–1200 m (300–3900 ft) |
Distribution |
FL; GA; NC; SC
|
CO; IA; IL; IN; KS; KY; MA; MN; MO; ND; NE; OH; OK; SD; WI; MB
|
Source | FNA vol. 19, p. 208. | FNA vol. 19, p. 211. |
Parent taxa | Asteraceae > tribe Vernonieae > Vernonia | Asteraceae > tribe Vernonieae > Vernonia |
Sibling taxa | ||
Synonyms | Chrysocoma acaulis | V. fasciculata subsp. corymbosa, V. fasciculata var. corymbosa |
Name authority | (Walter) Gleason: Bull. New York Bot. Gard. 4: 222. (1906) | Michaux: Fl. Bor.-Amer. 2: 94. (1803) |
Web links |