Centaurea sulphurea

Willdenow

Enum. Pl., 930. 1809.

Common names: Sicilian star-thistle sulphur-colored Sicilian thistle sulphur knapweed
Introduced
Treatment appears in FNA Volume 19. Treatment on page 194. Mentioned on page 182, 183.

Annuals, 10–100 cm. Stems simple to openly branched, branches ascending, villous to hispid with septate hairs and loosely tomentose. Leaves ± villous to hispid with septate hairs, minutely resin-gland-dotted; basal winged-petiolate, blades oblong to oblanceolate, 10–15 cm, margins pinnately lobed, lobes acute, finely dentate; cauline sessile, long-decurrent with narrow wings, linear-oblong to oblanceolate, 1–6 cm, entire or distally serrate with short, spine-tipped teeth. Heads disciform, borne singly or in open, few-headed corymbiform arrays, long-pedunculate. Involucres ovoid, 12–30 mm, distally constricted. Principal phyllaries: bodies greenish or stramineous, ovate to elliptic, glabrous, appendages spreading to reflexed, brown to blackish purple, each with palmately radiating cluster of spines, central spine stout, 1–2.5 cm, base dark-brown to black, distally stramineous. Inner phyllaries: appendages acute or spine-tipped. Florets many; corollas yellow, all ± equal, 25–35 mm; corollas of sterile florets slender, inconspicuous. Cypselae dark-brown, 5–8 mm, glabrous; pappi of many, brown to blackish, unequal bristles 6–7 mm. 2n = 24.


Phenology: Flowering spring–summer (May–Jul).
Habitat: Disturbed sites, grasslands, woodlands, pastures, roadsides
Elevation: 0–300 m

Discussion

Centaurea sulphurea is considered to be a noxious weed by the state of California.

Selected References

None.

Lower Taxa

None.

"fine" is not a number."fine" is not a number.

... more about "Centaurea sulphurea"
with fine , 1-celled hairs +  and glabrous +
scarious +
brown +  and blackish purple +
spreading;reflexed +
spine-tipped +  and acute +
corymbiform +  and open +
indeterminate +  and determinate +
David J. Keil +  and Jörg Ochsmann +
Willdenow +
winged-petiolate +
stramineous +, dark-brown +  and black +
decurrent +
Asteraceae tribe Cynareae +
compound +  and simple +
oblong;oblanceolate +
10 cm100 mm <br />0.1 m <br /> (15 cm150 mm <br />0.15 m <br />) +
stramineous +  and greenish +
10-nerved or 20-nerved +  and rugose +
ovate;elliptic +
tomentose +, villous +  and hispid +
barbed +  and smooth +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
linear-oblong +  and oblanceolate +
1 cm10 mm <br />0.01 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Sicilian star-thistle +, sulphur-colored Sicilian thistle +  and sulphur knapweed +
actinomorphic +
radial +  and bilateral +
inconspicuous +
expanded +  and slender +
2.5 cm25 mm <br />0.025 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
compressed +  and barrel--shaped +
fertile +  and bisexual +
Calif. +  and sw Europe +
0–300 m +
glandular-punctate +
puberulent +, strigose +, villous +, tomentose +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Disturbed sites, grasslands, woodlands, pastures, roadsides +
long-pedunculate +
in open , few-headed corymbiform arrays +  and singly +
indeterminate +
each +  and sessile +
constricted +
1.2 cm12 mm <br />0.012 m <br /> (3 cm30 mm <br />0.03 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
resin-gland-dotted +, less villous +  and hispid +
entire +  and dentate +
2-carpellate +
brown +  and blackish +
persistent +
Flowering spring–summer (May–Jul). +
papillate +  and smooth +
distinct +  and fused +
flat;convex +
exalbuminous +
Introduced +
simple +  and openly branched +
spreading +, ascending +  and erect +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
Acosta +, Cnicus +, Grossheimia +, Jacea +  and Leucacantha +
Centaurea sulphurea +
Centaurea +
species +
tomentose +  and glabrous +
10 cm100 mm <br />0.1 m <br /> (100 cm1,000 mm <br />1 m <br />) +
tree +, vine +, shrub +  and subshrub +
15 +, 13 +, 12 +, 11 +, 10 +, 9 +  and 8 +