Centaurea iberica

Treviranus ex Sprengel

Syst. Veg. 3: 406. 1826.

Common names: Iberian star thistle or knapweed
Introduced
Treatment appears in FNA Volume 19. Treatment on page 192. Mentioned on page 183.

Annuals, biennials, or short-lived perennials, 20–200 cm. Stems 1–several, divaricately much branched, often forming rounded mound, puberulent to loosely tomentose. Leaves hispidulous to loosely tomentose, ± glabrate, minutely resin-gland-dotted; proximal leaves petiolate, blades 10–20 cm, margins 1–2 times pinnately lobed or dissected, rosette with central cluster of spines; mid sessile, not decurrent, blades ± lanceolate, shorter; distal blades linear to oblong, entire to coarsely dentate or shallowly lobed. Heads disciform, borne singly or in leafy cymiform arrays, sessile or short-pedunculate. Involucres ovoid to hemispheric, (10–) 13–18 mm. Principal phyllaries: bodies greenish or stramineous, ovate, scarious–margined, appendages stramineous, spiny–fringed at base, each tipped by stout spreading spine (0.5–) 1–3 cm. Inner phyllaries: appendages truncate, spineless. Florets many; corollas white, pink, or pale-purple, those of sterile florets slender, 15–20 mm, those of fertile florets 15–20 mm. Cypselae white or brown-streaked, 3–4 mm, glabrous; pappi of white bristles 1–2.5 (–3) mm. 2n = 16, 20.


Phenology: Flowering summer (Jun–Sep).
Habitat: Roadsides, pastures, fields
Elevation: 0–1500 m

Distribution

V19-222-distribution-map.gif

Introduced; Calif., Kans., Oreg., Wash., Wyo., Europe, Asia

Discussion

Centaurea iberica is native to southeastern Europe through central Asia.

Iberian star thistle is considered to be a noxious weed in several states of the western United States. Weed control measures in Oregon and Washington have apparently eradicated the species in those states. Centaurea iberica is very similar to C. calcitrapa, from which it differs by its pappose cypselae and often more robust habit. The Kansas and Wyoming plants were originally reported as C. calcitrapa (R. L. McGregor 1986).

Selected References

None.

Lower Taxa

None.

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

... more about "Centaurea iberica"
with fine , 1-celled hairs +  and glabrous +
scarious +
spineless +, tipped +  and spiny-fringed +
erect;spreading +
less dentate or fringed linear +  and ovate +
cymiform +  and leafy +
indeterminate +  and determinate +
David J. Keil +  and Jörg Ochsmann +
Treviranus ex Sprengel +
decurrent +
Asteraceae tribe Cynareae +
compound +  and simple +
lanceolate +
10 cm100 mm <br />0.1 m <br /> (20 cm200 mm <br />0.2 m <br />) +
scarious-margined +
stramineous +  and greenish +
10-nerved or 20-nerved +  and rugose +
barbed +  and smooth +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Iberian star thistle or knapweed +
actinomorphic +
radial +  and bilateral +
white +  and blue pink purple or yellow +
inconspicuous +
expanded +  and slender +
brown-streaked +  and white +
compressed +  and barrel--shaped +
fertile +  and bisexual +
Calif. +, Kans. +, Oreg. +, Wash. +, Wyo. +, Europe +  and Asia +
0–1500 m +
glandular-punctate +
puberulent +, strigose +, villous +, tomentose +  and glabrous +
pistillate +, staminate +  and neuter +
pale-purple +, pink +  and white +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
fertile +  and sterile +
winged +  and beaked +
dispersed +
Roadsides, pastures, fields +
short-pedunculate +  and sessile +
in leafy cymiform arrays +  and singly +
indeterminate +
each +  and sessile +
1 cm10 mm <br />0.01 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
ovoid;hemispheric +
1.3 cm13 mm <br />0.013 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
resin-gland-dotted +, glabrate +, hispidulous +  and loosely tomentose +
acute +  and linear-oblong +
entire +  and dentate +
usually lobed +  and dissected +
1-2 times pinnately lobed or dissected rosette +
rounded +
2-carpellate +
persistent +
Flowering summer (Jun–Sep). +
papillate +  and smooth +
distinct +  and fused +
flat;convex +
exalbuminous +
Introduced +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
spreading +, ascending +  and erect +
1 +  and several +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
Acosta +, Cnicus +, Grossheimia +, Jacea +  and Leucacantha +
Centaurea iberica +
Centaurea +
species +
perennial +, short-lived +, biennial +  and annual +
tomentose +  and glabrous +
not decurrent +
20 cm200 mm <br />0.2 m <br /> (200 cm2,000 mm <br />2 m <br />) +
tree +, vine +, shrub +  and subshrub +
15 +, 13 +, 12 +, 11 +, 10 +, 9 +  and 8 +