Plectocephalus americanus

(Nuttall) D. Don in R. Sweet

in R. Sweet, Brit. Fl. Gard., ser. 2, 1: plate 51. 1830.

Common names: American basketflower powderpuff or thornless thistle American star-thistle cardo del valle
Basionym: Centaurea americana Nuttall J. Acad. Nat. Sci. Philadelphia 2: 117. 1821
Treatment appears in FNA Volume 19. Treatment on page 176. Mentioned on page 177.

Plants 50–200 cm. Stems usually 1, erect, sparingly branched, glabrous, minutely scabrous and glandular. Leaves scabrous; basal sessile or winged-petiolate, usually absent at anthesis, blades oblanceolate to narrowly obovate, 10–20 cm, margins entire or sparingly denticulate; cauline sessile, usually not much smaller except among heads, blades ovate to lanceolate, mostly 5–10 cm, entire or serrulate. Involucres broadly hemispheric, 30–50 mm. Phyllaries: bodies pale green, broadly elliptic (outer) to linear (inner), apices with appendages erect to spreading, whitish to stramineous (less commonly pale-brown to purple), fringed with 9–15 slender spinelike teeth 2–3 mm, teeth not conspicuously ciliate; mid with (4–) 5–7 (–8) pairs of lobes; faces glabrous or loosely cobwebby-tomentose. Corollas of neutral florets pink-purple (rarely white), 35–50 mm, enlarged, raylike; of bisexual florets pinkish, 20–25 mm. Cypselae grayish brown to black, 4–5 mm, glabrous or with white hairs near bases; pappus bristles unequal, stiff, 6–14 mm. 2n = 26.


Phenology: Flowering Feb–Aug.
Habitat: Prairies, fields, open woods, grasslands, roadsides, other disturbed sites
Elevation: 0–2100 m

Distribution

V19-196-distribution-map.gif

Ariz., Ark., Kans., La., Mo., Okla., Tex., Mexico (Chihuahua), Mexico (Coahuila), Mexico (Nuevo León), Mexico (San Luis Potosí), Mexico (Tamaulipas)

Discussion

Plectocephalus americanus is an attractive and showy plant and has been in cultivation for many years. It occasionally escapes from cultivation outside its native range.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Plectocephalus americanus"
whitish;stramineous +
fringed +
expanded +
scarious +
erect;spreading +
fringed +  and triangular +
cymiform +  and open +
indeterminate +  and determinate +
puberulent +  and glabrous +
compressed +, barrel--shaped +, obovoid +  and oblique +
David J. Keil +
(Nuttall) D. Don in R. Sweet +
winged-petiolate +  and sessile +
decurrent +
Centaurea americana +
compound +  and simple +
serrulate +  and entire +
ovate;lanceolate +
5 cm50 mm <br />0.05 m <br /> (10 cm100 mm <br />0.1 m <br />) +
broadly elliptic;linear +
pale green +
10-nerved or 20-nerved +  and rugose +
American basketflower +, powderpuff or thornless thistle +, American star-thistle +  and cardo del valle +
actinomorphic +  and zygomorphic +
pale-yellow +, cream +, purple +  and pink +
bent +  and elongate +
expanded +
grayish brown +  and black +
with white hairs +  and glabrous +
compressed +, 4-5-angled +, terete +, rounded-prismatic +, ovoid +, obovoid +  and ellipsoid +
fertile +  and bisexual +
Ariz. +, Ark. +, Kans. +, La. +, Mo. +, Okla. +, Tex. +, Mexico (Chihuahua) +, Mexico (Coahuila) +, Mexico (Nuevo León) +, Mexico (San Luis Potosí) +  and Mexico (Tamaulipas) +
0–2100 m +
glandular-punctate +
cobwebby-tomentose +  and glabrous +
pistillate +, staminate +  and neuter +
2 cm20 mm <br />0.02 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
winged +  and beaked +
dispersed +
Prairies, fields, open woods, grasslands, roadsides, other disturbed sites +
in open cymiform arrays +, singly +  and radiant +
indeterminate +
each +  and sessile +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
hemispheric +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
deltate +, usually narrowly triangular +  and more or less linear +
entire +  and dentate +
denticulate +  and entire +
2-carpellate +
0.6 cm6 mm <br />0.006 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
persistent +
fistulose +
Flowering Feb–Aug. +
papillate +  and smooth +
distinct +  and fused +
in R. Sweet, Brit. Fl. Gard., ser. +
flat;convex +
exalbuminous +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
Centaurea sect. Plectocephalus +
Plectocephalus americanus +
Plectocephalus +
species +
cylindric +
elongate +
slender +
30 cm300 mm <br />0.3 m <br /> (200 cm2,000 mm <br />2 m <br />) +