font settings and languages

Font Size: Large | Normal | Small
Font Face: Verdana | Geneva | Georgia
Languages:

Centaurea iberica

(Iberian Knapweed, Iberian Star Thistle, Iberian Starthistle, Iberian Starthistle Centaurea Iberica)

Common Names

[ Back to top ]

Click on the language to view common names.

Common Names in English:

Iberian Knapweed, Iberian Star Thistle, Iberian Starthistle, Iberian Starthistle Centaurea Iberica, Knapweed

Common Names in Portuguese:

Centáurea-Gigante

Description

[ Back to top ]

Genus Centaurea

Annuals , biennials, or perennials, 20-300 cm, glabrous or tomentose . Stems erect , ascending , or spreading , simple or branched. Leaves basal and cauline; petiolate or sessile; proximal blade margins often ± deeply lobed , (spiny in C. benedicta ), distal ± smaller, often entire , faces glabrous or ± tomentose, sometimes also villous , strigose , or puberulent , often glandular-punctate. Heads discoid , disciform , or radiant, borne singly or in corymbiform arrays. Involucres cylindric or ovoid to hemispheric . Phyllaries many in 6-many series, unequal, proximal part appressed , body margins entire. distal parts expanded into erect to spreading, usually ± dentate or fringed , linear to ovate appendages , spine. tipped or spineless. Receptacles flat, epaleate, bristly . Florets 10-many; outer usually sterile , corollas slender and inconspicuous to much expanded, ± bilateral ; inner fertile , corollas white to blue, pink, purple, or yellow, bilateral or radial , often bent at junction of tubes and throats , lobes linear-oblong, acute; anther bases tailed , apical appendages oblong ; style branches: fused portions with minutely hairy nodes, distinct portions minute. Cypselae ± barrel-shaped, ± compressed , smooth or ribbed , apices entire (denticulate in C. benedicta ), glabrous or with fine, 1-celled hairs , attachment scar . lateral (with or without elaiosomes) ; pappi 0 or ± persistent , of 1-3 series of smooth or minutely barbed , stiff bristles or narrow scales . x = 8, 9, 10, 11, 12, 13, 15.

Species ca. 500: introduced ; Eurasia , n Africa, widely introduced worldwide.

Taxonomic limits of Centaurea have been controversial. The genus has great morphologic diversity , and studies have revealed much cytologic (e.g. , N. Garcia-Jacas et al. 1996) and palynologic (e.g., G. Wagenitz 1955) variation as well. During the nineteenth and twentieth centuries, various taxonomists attempted, with limited success, to divide Centaurea into smaller genera or workable infrageneric taxa. The relations of several satellite genera have been controversial as well.

Recent molecular phylogenetic studies (A. Susanna et al. 1995; N. Garcia-Jacas et al. 2000, 2001) have begun to clarify relationships within Centaurea and between Centaurea and other genera. These studies make it clear that Centaurea as traditionally defined is polyphyletic, and that generic boundaries should be realigned if monophyletic taxa are to be recognized. Some taxa traditionally included within Centaurea (e.g., the two native North American species, Centaurea americana and C. rothrockii) fall outside the redefined generic boundaries and are here treated in Plectocephalus. Others usually placed into segregate genera (e.g., Cnicus benedictus) are firmly nested within Centaurea. Because the type species of Centaurea (C. centaurium Linnaeus, an African species) falls outside the main lineage of the genus, a proposal has been made to conserve Centaurea with a different type species (W. Greuter et al. 2001), thereby maintaining the nomenclatural stability of most of the numerous species that do fall within the principal Centaurea clade.

Although several Centaurea species are widely established as members of the North American flora , and some of these are widely distributed invasive weeds , some of the taxa listed by J. T. Kartesz and C. A. Meacham (1999) are apparently waifs and not permanent members of the flora. These taxa are discussed informally immediately below.

Although Cnicus has usually been recognized as a distinctive monotypic genus, it has been merged into Centaurea by various authors (e.g., K . Bremer 1994; G. Wagenitz and F. H. Hellwig 1996) . Recent molecular systematic studies (N. Garcia-Jacas et al. 2000) provide additional evidence that it is nested within Centaurea.David J. Keil, Jörg Ochsmann "Centaurea". in Flora of North America Vol. 19, 20 and 21 Page 52, 57, 58, 67, 83, 84, 96, 171, 172, 176, 177, EFloras.org.

Physical Description

Species Centaurea iberica

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. [source]

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). [source]

Habit: Forb/herb

Flowers: Bloom Period: May, June, July, August, September. • Flower Color: lavender, purple, violet

Size/Age/Growth

Size: 36-48" tall.

Habitat

Roadsides, pastures, fields ; 0-1500 m. Centaurea iberica is native to southeastern Europe through central Asia (Ref. 52813).

 

Biology

[ Back to top ]

Reproduction

Duration: Perennial

Growth

Culture: Space 24-36" apart.

Soil: Minimum pH: 6.1 • Maximum pH: 7.8

Sunlight: Sun Exposure: Full Sun .

Moisture: Drought Tolerance: High

Temperature: Cold Hardiness: Not Applicable (map)

Taxonomy

[ Back to top ]

Unambiguous Synonyms

  1. Centaurea iberica Trev. ex Spreng.
  2. Centaurea iberica Trev. ex Sprengel
  3. Centaurea iberica Trevir. ex Spreng.

Notes

Name Status: Accepted Name . Latest taxonomic scrutiny: 15-Mar-2000

Place of publication : Syst. veg. 3:406. 1826

Name verified on 11-Jun-1991 by ARS Systematic Botanists. Last updated: 22-May-1997

Similar Species

[ Back to top ]

Members of the genus Centaurea

There are approximately 2566 species in this genus. Here are just 100 of them:

C. 'Caramia' · C. 'John Coutts' · C. 'Jordy' · C.'Nigra' (Bachelor Buttons) · C. abbreviata · C. abchasica · C. abdelkaderi · C. abdelkaridi · C. abnormis · C. abrotanifolia · C. absinthifolia · C. abyssinica · C. acanthodes · C. acarnanica · C. acaulis · C. acaulis subsp. boissieri · C. achaia · C. achaia achaia · C. achaia subsp. corinthiaca · C. achtarovii · C. achtarovii subsp. sooana · C. acicularis · C. acmophylla · C. acrolepis · C. acromaura · C. acuta · C. acutangula · C. acutifolia · C. acutiloba · C. adami · C. adamovicii · C. adeana · C. adjarica · C. adonidifolia · C. adpressa · C. adulterina · C. adusta · C. aegialophila · C. aegyptiaca · C. aemiliae · C. aemilii · C. aemula · C. aemulans · C. aeolica · C. aeolica subsp. pandataria · C. aetaliae · C. aetolica · C. affinis · C. affinis candida · C. affinis denudata · C. affinis lacerata · C. affinis subsp. balcanica · C. affinis subsp. candida · C. affinis subsp. chalcidicea · C. affinis subsp. denudata · C. affinis subsp. lacerata · C. affinis subsp. peloponesiaca · C. affinis subsp. tartarea · C. africana · C. aggregata · C. ahverdovii · C. aichingeriana · C. ainetensis · C. aintabica · C. aintansis · C. ajtayana · C. akamantis · C. aksamica · C. aladaghensis · C. alaica · C. alata · C. alba · C. alba albanica · C. alba brunnea · C. alba euxina · C. alba maluqueri · C. alba princeps · C. alba subsp. albanica · C. alba subsp. brunnea · C. alba subsp. caliacrae · C. alba subsp. ciliata · C. alba subsp. costae · C. alba subsp. diomedea · C. alba subsp. epapposa · C. alba subsp. euxina · C. alba subsp. formanekii · C. alba subsp. heldreichii · C. alba subsp. ipecensis · C. alba subsp. latronum · C. alba subsp. leucomalla · C. alba subsp. macrocephala · C. alba subsp. maluqueri · C. alba subsp. montsicciana · C. alba subsp. sterilis · C. alba subsp. strepens · C. alba subsp. subciliaris · C. alba subsp. tartesiana · C. alba subsp. tenoreana · C. alba subsp. vandasii · C. alba tartesiana

Bibliography

[ Back to top ]

More Info

[ Back to top ]

Notes

[ Back to top ]

Contributors

Data Sources

Accessed through GBIF Data Portal February 16, 2008:

Identifiers

Footnotes

Last Revised: August 24, 2008