Prenanthes barbata

(Torrey & A. Gray) Milstead ex Cronquist

Brittonia 29: 223. 1977.

Common names: Barbed rattlesnakeroot
Endemic
Basionym: Nabalus fraseri var. barbatus Torrey & A. Gray Fl. N. Amer. 2: 481. 1843
Synonyms: Prenanthes serpentaria var. barbata (Torrey & A. Gray) A. Gray
Treatment appears in FNA Volume 19. Treatment on page 267. Mentioned on page 265, 268.

Plants 50–150 cm; taproots thickened, tuberous, with lateral side roots. Stems erect, purplish, glabrous proximally, finely tomentulose or setose distally. Leaves: proximal withered by flowering; petiolate (petioles 2–3 cm, winged); blades ± elliptic, 4–10 × 1–4 cm, coriaceous, bases narrowed (not hastate), margins coarsely and irregularly dentate or serrate (unlobed), apices acute, faces glabrous or papillose-hispid; mid cauline cuneate or sessile and clasping; distal sessile and reduced. Heads (15–50) in (much-branched) paniculiform or thyrsiform arrays (nodding). Calyculi of 7–11, dark green to purple, triangular to lanceovate bractlets 2–5 mm, hispid or setose along midveins. Involucres cylindric to campanulate, 12–16 × 4–6 mm. Phyllaries 6–8, usually purple or lavender, subulate to lanceolate, 11–14 mm, margins scarious, coarsely hispid or setose along midveins. Florets 10–15; corollas white to yellowish white, 13–16 mm. Cypselae tan, subcylindric, subterete to 5-angled, 8–10 mm, indistinctly 8–10-ribbed; pappi yellowish white, 7–8 mm.


Phenology: Flowering Aug–Oct.
Habitat: Sandy oak-hickory-pine woods, savannas, prairies, pine barrens
Elevation: 10–100 m

Distribution

V19-364-distribution-map.gif

Ala., Ark., Ga., Ky., La., Okla., Tenn., Tex.

Discussion

Prenanthes barbata is identified by its erect habit, irregularly dentate leaves, heads with 6–8 purple phyllaries, coarsely setose calyculi and phyllaries, and white to yellowish white corollas.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Prenanthes barbata"
not beaked +  and truncate +
scarious +
ovate +  and lanceolate +
thyrsiform +  and paniculiform +
indeterminate +  and determinate +
David J. Bogler +
(Torrey & A. Gray) Milstead ex Cronquist +
narrowed +
Nabalus fraseri var. barbatus +
compound +  and simple +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
deltate;triangular or ovate +
coriaceous +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
tuberculate +, rugose +, muricate +  and smooth +
setose +  and hispid +
triangular;linear-lanceolate or subulate +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
filiform +
Barbed rattlesnakeroot +
zygomorphic +, actinomorphic +  and (3-)5-merous +
white +  and yellowish white +
1.3 cm13 mm <br />0.013 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
subterete +  and 5-angled +
Ala. +, Ark. +, Ga. +, Ky. +, La. +, Okla. +, Tenn. +  and Tex. +
10–100 m +
papillose-hispid +  and glabrous +
winged +  and beaked +
dispersed +
Sandy oak-hickory-pine woods, savannas, prairies, pine barrens +
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 /> (1.6 cm16 mm <br />0.016 m <br />) +
cylindric;campanulate +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
sessile +  and petiolate +
cauline +  and mid +
cuneate +
serrate +  and dentate +
setose +  and hispid +
2-carpellate +
yellowish white +
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 +
subequal +  and unequal +
1.1 cm11 mm <br />0.011 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
exalbuminous +
setose +, tomentulose +  and glabrous +
1 +  and 5 +
appendaged +  and truncate +
papillate +
Prenanthes serpentaria var. barbata +
Prenanthes barbata +
Prenanthes +
species +
dentate +, serrate +  and entire +
5 cm50 mm <br />0.05 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +