Vernonia acaulis |
Vernonia baldwinii |
|
---|---|---|
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 |
FL; GA; NC; SC
|
AR; CO; IA; IL; KS; KY; LA; MI; MO; NE; OK; TX
|
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 | ||
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) |
Web links |