Centaurea iberica (Iberian Knapweed)

Interesting Facts

[ Back to top ]

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 ]

Family Compositae

The largest family of flowering plants , the Compositae (Asteraceae), comprising about 1,100 genera and more than 20,000 species and characterized by many small flowers arranged in a head looking like a single flower and subtended by an involucre of bracts. A head may consist of both ray flowers and disk flowers, as in the sunflower, of disk flowers only, as in the burdock, or of ray flowers only, as in the dandelion.

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.[1]

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 [2].

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 ]

Domain: Eukaryota () - Whittaker & Margulis,1978 - eukaryotes
- Kingdom: Plantae () - Haeckel, 1866 - Plants
  - Subkingdom: Viridaeplantae () - Cavalier-Smith, 1981
    - Phylum: Tracheophyta () - Sinnott, 1935 ex Cavalier-Smith, 1998 - Vascular Plants
      - Subphylum: Euphyllophytina ()
        Class: Spermatopsida () - Brongniart, 1843
        Subclass: Asteridae () - Takhtajan, 1967
        Superorder: Campanulanae () - Takhtajan Ex Reveal, 1992
        Order: Asterales () - Lindley, 1833
        Family: Compositae () - Giseke, 1792, nom. cons., nom. alt.
        Subfamily: Carduoideae ()
        Tribe: Cardueae ()
        Subtribe: Centaureinae ()
        Genus: Centaurea () - C. Linnaeus, 1753 - Knapweed, star thistle, cornflower [Greek kentaurieon, ancient plant name associated with Chiron, a centaur famous for knowledge of medicinal plants]
        Specific epithet: iberica - Trevir. ex Spreng.
        Botanical name: - Centaurea iberica Trevir. ex Spreng.

Notes

Name Status: Accepted Name .

Comment: Data Providers: New Zealand Plant Name Database, Govaerts World Compositae Checklist A-G, IPNI, Flora of China Checklist, Tropicos, Euro+Med. GCC LSID: urn :lsid:compositae.org:names:74BE79A8-D10C-4243-B1F1-B7E2BF6A9230

Last scrutiny: 20-Aug-09

Similar Species

[ Back to top ]

Members of the genus Centaurea

ZipcodeZoo has pages for 82 species, subspecies, varieties, forms, and cultivars in this genus:

More Info

[ Back to top ]

Search for Pictures: images.google.com
Search for Scholarly Articles: Google Scholar
Search using Scientific Name and Vernacular Names: All the Web | AltaVista Canada | AltaVista | Excite | Google | HotBot | Lycos
Search using Specialized Databases: GenBank | Medline | Scirus | CISTI/CAL | Agricola Periodicals | Agricola Books

Notes

[ Back to top ]

Contributors

Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed March 27, 2012.

Data Sources

Accessed through GBIF Data Portal February 16, 2008:

Australian National Herbarium
, Australian National Herbarium
Berkeley Natural History Museums, University and Jepson Herbaria DiGIR provider
Israel Nature and Parks Authority, Israel Nature and Parks Authority
Oregon State University, Vascular Plant Collection
The Swedish Museum of Natural History
, Lund Botanical Museum
UK National Biodiversity Network, Botanical Society of the British Isles - Vascular Plants Database
USDA PLANTS, USDA PLANTS Database

Identifiers

Biodiversity Heritage Library NamebankID: 2658260
Catalogue of Life Accepted Name Code: Ast-7488
Global Biodiversity Information Facility Taxonkey: 13749284
Globally Unique Identifier: urn:lsid:ipni.org:names:190696-1
GRIN Nomen Number: 316084
Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 36961
Natural Heritage Network Species Identifier: PDAST1Y090
U.S.D.A. Plant Symbol: CEIB
Zipcode Zoo Species Identifier: 27158

Footnotes

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. [back]
"Centaurea iberica". in Flora of North America Vol. 19, 20 and 21 Page 183, 192. Oxford University Press. Online at EFloras.org. [back]

Centaurea iberica

Interesting Facts

Common Names

Description

Family Compositae

Genus Centaurea

Physical Description

Species Centaurea iberica

Size/Age/Growth

Habitat

Biology

Reproduction

Growth

Taxonomy

Notes

Similar Species

Members of the genus Centaurea

More Info

Further Reading

Notes

Contributors

Data Sources

Identifiers

Footnotes