Prenanthes serpentaria

Pursh

Fl. Amer. Sept. 2: 499, plate 24. 1813.

Common names: Cankerweed lion’s-foot gall-of-the-earth butterweed
IllustratedEndemic
Synonyms: Nabalus fraseri de Candolle Nabalus integrifolius Cassini Nabalus serpentarius (Pursh) Hooker Prenanthes integrifolia (Cassini) Small
Treatment appears in FNA Volume 19. Treatment on page 270. Mentioned on page 265, 271.

Plants 50–200+ cm; taproots short and thick, with lateral storage roots. Stems erect, green to reddish or purple mottled, proximally glabrous, distally sparsely tomentulose. Leaves: proximal often withered by flowering; petiolate (petioles 1–10 cm, often with pair of lobes); blades deltate to ovate or elliptic, 5–20 × 4–10 cm, coriaceous, margins usually deeply, pinnately 3–5-lobed, lobes and sinuses large and ± rounded, sometimes deeply cleft to base or palmately divided, apices acute or obtuse, ultimate margins entire or dentate, faces glabrous or finely tomentose on veins; cauline sessile or petiolate; distal reduced in size and lobing, often entire. Heads (6–12 in nodding clusters) in broad, paniculiform to corymbiform arrays (often widely branching and subdichotomous, at least some branches elongate). Calyculi of 8–10, green to purple, triangular to subulate bractlets 1–4 mm, often tomentulose to setose. Involucres cylindric (often attenuate basally to bracteate peduncles), 12–15 × 4–5 mm. Phyllaries (7–) 8– (10), green or often purple, narrowly lanceolate to elliptic, 10–13 mm, sparsely hispid to appressed, coarsely setose, often reduced to single coarse, appressed seta (setae green or tan). Florets (8–) 10–14 (–19); corollas usually yellow to pale-yellow, 9–15 mm. Cypselae golden brown to light tan, subcylindric, subterete or angled, 5–8 mm, indistinctly 8–10-ribbed; pappi tan, 7–8 mm. 2n = 16.


Phenology: Flowering Aug–Oct.
Habitat: Oak-hickory woodlands, borders, oak flats, pine woods, sandy areas
Elevation: 100–1700 m

Distribution

V19-371-distribution-map.gif

Ala., Conn., Del., D.C., Fla., Ga., Ky., Md., Mass., Miss., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Va., W.Va.

Discussion

Prenanthes serpentaria is generally recognized by its large, deeply 3–5-lobed proximal leaves with rounded sinuses and lobes, winged petioles, attenuate involucres, sparsely setose phyllaries, and yellow corollas. The leaves are variable in size and lobing, often on the same plant. Some specimens have predominantly ovate to elliptic, unlobed leaves, and these have been variously recognized. Some specimens appear to combine characteristics of P. crepidinea or P. trifoliolata and may be the result of recent or ancient hybridization. The species boundaries in this group merit further study.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Prenanthes serpentaria"
not beaked +  and truncate +
obtuse;acute;divided +
scarious +
ovate +  and lanceolate +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
David J. Bogler +
decurrent +
compound +  and simple +
5 cm50 mm <br />0.05 m <br /> (20 cm200 mm <br />0.2 m <br />) +
deltate;ovate or elliptic +
coriaceous +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
tuberculate +, rugose +, muricate +  and smooth +
tomentulose +  and setose +
triangular;linear-lanceolate or subulate +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
filiform +
petiolate +  and sessile +
Cankerweed +, lion’s-foot +, gall-of-the-earth +  and butterweed +
zygomorphic +, actinomorphic +  and (3-)5-merous +
usually yellow +  and pale-yellow +
0.9 cm9 mm <br />0.009 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
golden brown +  and light tan +
angled +, subterete +  and subcylindric +
Ala. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Ky. +, Md. +, Mass. +, Miss. +, N.J. +, N.Y. +, N.C. +, Ohio +, Pa. +, R.I. +, S.C. +, Tenn. +, Va. +  and W.Va. +
100–1700 m +
tomentose +  and glabrous +
winged +  and beaked +
dispersed +
Oak-hickory woodlands, borders, oak flats, pine woods, sandy areas +
indeterminate +
each +  and sessile +
0.2 cm2 mm <br />0.002 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
cauline +  and basal +
rounded +
3-5-lobed +
2-carpellate +
persistent +
0.7 cm7 mm <br />0.007 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
Flowering Aug–Oct. +
connate +  and distinct +
setose +  and hispid +
single +  and 8 +
1 cm10 mm <br />0.01 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
Fl. Amer. Sept. +
exalbuminous +
Illustrated +  and Endemic +
green +  and reddish or purple mottled +
tomentulose +  and glabrous +
1 +  and 5 +
appendaged +  and truncate +
papillate +
Nabalus fraseri +, Nabalus integrifolius +, Nabalus serpentarius +  and Prenanthes integrifolia +
Prenanthes serpentaria +
Prenanthes +
species +
5 cm50 mm <br />0.05 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +