Prenanthes autumnalis

Walter

Fl. Carol., 193. 1788.

Common names: Slender rattlesnakeroot
Endemic
Synonyms: Nabalus virgatus de Candolle Prenanthes virgata Michaux
Treatment appears in FNA Volume 19. Treatment on page 267. Mentioned on page 264.

Plants 40–140 cm; taproots thickened, tuberous. Stems 1–5, erect, mostly green with mottled purple, slender, simple, glabrous. Leaves: proximal present at flowering; petiolate (petioles winged); blades oblong to linear, 7–18 × 0.5–6 cm, coriaceous, bases attenuate, margins deeply pinnately lobed or divided, lobes narrow and at right angles, apices acute to acuminate, faces glabrous or slightly glabrate along veins; distally sessile and much reduced. Heads (1–2 in pedunculate lateral clusters) in spiciform or racemiform arrays. Involucres cylindro-campanulate, 10–13 × 3–4 mm. Calyculi of 6–8, green to purple, triangular to subulate bractlets 1–4 mm. Phyllaries 7–8, pink or purple, linear to elliptic, 8–13 mm, glabrous. Florets 8–10; corollas usually pinkish, sometimes lavender or white, 11–17 mm. Cypselae dark green, elliptic to linear, subterete to angular, 3.5–5.5 mm, indistinctly 8–10-ribbed; pappi pale-yellow to tan, 5 mm.


Phenology: Flowering Aug–Oct.
Habitat: Coastal plain, low savannas, sandy pinelands, moist places, swales
Elevation: 0–200 m

Distribution

V19-363-distribution-map.gif

Del., Fla., Ga., Md., Miss., N.J., N.C., S.C., Va.

Discussion

Prenanthes autumnalis is recognized by its erect, slender habit, pinnately lobed proximal leaves, narrowly racemiform or spiciform arrays of heads, glabrous phyllaries, and usually pinkish corollas.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Prenanthes autumnalis"
not beaked +  and truncate +
acute;acuminate +
scarious +
ovate +  and lanceolate +
racemiform +  and spiciform +
indeterminate +  and determinate +
David J. Bogler +
Walter +
attenuate +
compound +  and simple +
7 cm70 mm <br />0.07 m <br /> (18 cm180 mm <br />0.18 m <br />) +
oblong;linear +
coriaceous +
0.5 cm5 mm <br />0.005 m <br /> (6 cm60 mm <br />0.06 m <br />) +
tuberculate +, rugose +, muricate +  and smooth +
triangular;linear-lanceolate or subulate +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
filiform +
Slender rattlesnakeroot +
zygomorphic +, actinomorphic +  and (3-)5-merous +
white +, lavender +  and pinkish +
1.1 cm11 mm <br />0.011 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
subterete +  and angular +
Del. +, Fla. +, Ga. +, Md. +, Miss. +, N.J. +, N.C. +, S.C. +  and Va. +
0–200 m +
glabrate +  and glabrous +
winged +  and beaked +
dispersed +
Coastal plain, low savannas, sandy pinelands, moist places, swales +
indeterminate +
each +  and sessile +
0.2 cm2 mm <br />0.002 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
cylindro-campanulate +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
reduced +
divided +  and lobed +
2-carpellate +
pale-yellow +  and tan +
persistent +
5 cm50 mm <br />0.05 m <br /> (?) +
Flowering Aug–Oct. +
linear +  and elliptic +
connate +  and distinct +
subequal +  and unequal +
0.8 cm8 mm <br />0.008 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
Fl. Carol., +
exalbuminous +
green with mottled purple +
1 +  and 5 +
slender +
appendaged +  and truncate +
papillate +
Nabalus virgatus +  and Prenanthes virgata +
Prenanthes autumnalis +
Prenanthes +
species +
dentate +, serrate +  and entire +
5 cm50 mm <br />0.05 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +