Centaurea americana

• Overview
• Interesting Facts
• Common Names
• Description
• Biology
• Taxonomy
• Similar Species
• More Info
• Further Reading
• Notes

Overview

Interesting Facts

Common Names

Description

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

Habitat

Typically found at an altitude of 0 to 2,647 meters (0 to 8,684 feet).[2]

Biology

Reproduction

Duration: Annual

Growth

Culture: Space 12-15" apart.

Soil: Minimum pH: 6.1 • Maximum pH: 7.8

Sunlight: Sun Exposure: Full Sun .

Temperature: Cold Hardiness: Not Applicable (map)

Taxonomy

Synonyms

Plectocephalus Americanus

Notes

Name Status: Accepted Name .

Comment: Data Providers: CONABIO, SANBI, Flora Malesiana, Govaerts World Compositae Checklist A-G, IPNI, Tropicos. GCC LSID: urn :lsid:compositae.org:names:3EFB1743-AF34-480F-BCCD-95B6753943FC

Last scrutiny: 11-Aug-09

Similar Species

Members of the genus Centaurea

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

C. akamantis (Akamas Centaury) · C. alpestris (Greater Centaury) · C. americana (American Basketflower) · C. americana 'Aloha' (American Knapweed) · C. americana 'Jolly Joker' (American Knapweed) · C. aspera (Rough Star-Thistle) · C. atropurpurea (Centaurea) · C. bella (Knapweed) · C. benoistii (Maroon Cornflower) · C. biebersteinii (Ballast Waif Centaurea Biebersteinii) · C. bovina (Pasture Knapweed) · C. cachinalensis (Flor Del Minero) · C. calcitrapa (Big-Head Purple Starthistle) · C. calcitrapoides (Smallhead Star-Thistle) · C. cineraria (Dusty Miller) · C. cineraria 'Colchester White' (Dusty Miller) · C. crupina (Crupina) · C. cyanoides 'Blue Carpet' (Cornflower) · C. cyanus (Bachelor's Button) · C. cyanus nana 'Jubilee Gem' (Bachelors Button) · C. cyanus 'Black Ball' (Bachelors Button) · C. cyanus 'Black Boy' (Bachelors Button) · C. cyanus 'Black Gem' (Bachelors Button) · C. cyanus 'Black Magic' (Bachelors Button) · C. cyanus 'Blue Boy' (Bachelors Button) · C. cyanus 'Blue Diadem' (Bachelors Button) · C. cyanus 'Classic Blue' (Bachelors Button) · C. cyanus 'Dwarf Blue Midget' (Bachelors Button) · C. cyanus 'Frosted Queen Mix' (Bachelors Button) · C. cyanus 'Frosty Mix' (Bachelors Button) · C. cyanus 'Mauve Queen' (Bachelors Button) · C. cyanus 'Polka Dot Mix' (Bachelors Button) · C. dealbata (Knapweed Centaurea Dealbata) · C. dealbata 'Rosea' (Knapweed) · C. debeauxii (Meadow Knapweed) · C. debeauxii thuillieri (Meadow Knapweed) · C. debeauxii subsp. thuillieri (Meadow Knapweed) · C. depressa (Centaurea) · C. diffusa (Diffuse Knapweed) · C. diluta (North African Knapweed) · C. eriophora (Sand-Heath) · C. gymnocarpa (Velvet Centaurea) · C. hypoleuca DC. 'John Coutts' (Knapweed) · C. iberica (Iberian Knapweed) · C. jacea (Brown Knapweed) · C. jacea x nigra (Hybrid Knapweed Centaurea Jacea X Nigra) · C. macrocephala (Armenian Basketflower) · C. melitensis (Cockspur Thistle) · C. moncktonii (Meadow Knapweed) · C. montana (Mountain Bluet) · C. montana 'Alba' (Mountain Bluet) · C. montana 'Amethyst in Snow' (Mountain Bluet) · C. montana 'Dot Purple' (Mountain Bluet) · C. montana 'Gold Bullion' (Batchelor's Button) · C. moschata 'Dairy Maid' (Sweet Sultan) · C. moschata 'Imperialis' (Sweet Sultan) · C. moschata 'The Bride' (Sweet Sultan) · C. nigra (Black Knapweed) · C. nigrescens (Short-Fringe Starthistle) · C. orientalis (Centaurea) · C. ovina (Lilac Knapweed) · C. paniculata (Jersey Knapweed) · C. phrygia (Scandinavian Starthistle) · C. pindicola (Centaurea) · C. pulcherrima (Pink Bachelors Button) · C. 'Pulchra Major' (Bachelor's Button) · C. ragusina (Dubrovacka Zecina) · C. rothrockii (Basket Flower) · C. scabiosa (Great Starthistle) · C. solstitialis (Barnaby Star-Thistle) · C. solstitialis solstitialis (St. Barnaby's Thistle) · C. stoebe (Spotted Knapweed) · C. sulphurea (Sicilian Starthistle) · C. thuillieri (Meadow Knapweed) · C. transalpina (Alpine Knapweed) · C. trichocephala (Feather-Head Knapweed) · C. triumfetti (Squarrose Knapweed Centaurea Triumfetti) · C. triumfettii (Spreading Thistle) · C. uniflora (Single-Flower Knapweed) · C. uniflora nervosa (Singleflower Knapweed) · C. xpratensis (Meadow Knapweed) · C.'Nigra' (Bachelor Buttons)

More Info

• 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

Further Reading

• A little book of annuals, New York, The A. T. De La Mare company, inc., 1922. url p. 113.
• A practical guide to garden plants, containing descriptions of the hardiest and most beautiful annuals and biennials, hardy herbaceous and bulbous perennials, hardy water and bog plants, flowering and ornamental trees and shrubs, conife London;Longmans, Green, 1901. url , p. 549, p. 86.
• A report upon the grasses and forage plants of central Texas. By H.L. Bentley. .. Washington, Govt. print. off., 1898. url p. 31, p. 37.
• A textbook of botany for colleges and universities. .. Cincinnati [etc]American book company[1910-11] url .
• Addisonia: colored illustrations and popular descriptions of plants. New York: New York Botanical Garden, 1916-[1964]. url p. 57.
• An illustrated flora of the northern United States, Canada and the British possessions: from Newfoundland to the parallel of the southern boundary of Virginia and from the Atlantic Ocean westward to the 102nd meridian / by Nathaniel Lord Britton and Hon. Addison Brown. New York: Scribner, 1913. url p. 556, p. 559.
• Annotated list of the ferns and flowering plants of New York state, by Homer D. House. Albany, The University of the state of New York, 1924. url p. 747.
• Annual report Missouri Botanical Garden. 20 1909 St. Louis: Board of Trustees, 1890-1912. url p. 171, p. 175, p. 209.
• Anzeiger der Kaiserlichen Akademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Classe. Wien: Der Akademie, 1864-1914. url p. 472.
• Bartonia;proceedings of the Philadelphia botanical club. .. 47 - 51 1980 - 19 Philadelphia, Philadelphia Botanical Club, Academy of Natural Sciences. url p. 4.
• Biologia centrali-americana; or, Contributions to the knowledge of the fauna and flora of Mexico and Central America. London, Pub. for the editors by R. H. Porter and Dulau & co., 1879-88. url .
• Boston journal of natural history. 5 1845 - 18 Boston, Boston Society of Natural History. url p. 222, p. 498.
• Britton, N. L. (ed.). North American flora. 7 1922 [New York]New York Botanical Garden. url p. 512, p. 876.
• Brooklyn Botanic Garden record. 22 1933 [Brooklyn]: Brooklyn Botanic Garden, 1912-44. url p. 9.
• Bulletin / U.S. Department of Agriculture, Bureau of Plant Industry. Washington: G.P.O., 1901-1913. url p. 320.
• Bulletin of miscellaneous information /Royal Botanic Gardens, Kew. 1901 London: H.M. Stationery Office, 1900-1941. url p. 8.
• Bulletin of the Torrey Botanical Club. 48 1921 New York: Torrey Botanical Club, 1870-1996 url p. 32, p. 355.
• Catalog of hymenoptera in America north of Mexico / prepared cooperatively by specialists on the various groups of Hymenoptera under the direction of Karl V. Krombein. .. [et al.]. Washington: Smithsonian Institution Press, 1979- url p. 2144.
• Compositae newsletter. Columbus, Ohio: Dept. of Botany, Ohio State University, 1975- url p. 25, p. 4, p. 9.
• Contributions from the United States National Herbarium 26 1940 Washington, D.C.: Smithsonian Institution Press, 1890- url p. 263, p. 535, p. 749, p. V.
• Curtis's botanical magazine. 1-130 1906 London; New York [etc.]: Academic Press [etc.] url p. 39.
• Edwards's botanical register. 26 1840 London: James Ridgway, 1829-1847. url , .
• Experiment station record. Washington: G.P.O., 1889-1946. url p. 1135, p. 343.
• Flora of Bermuda. .. by Nathaniel Lord Britton. .. New York, C. Scribner's sons, 1918. url p. 407, p. 566.
• Flora of Bermuda... by Nathaniel Lord Britton... New York, Scribner, 1918. url p. 407, p. 566.
• Flora of Illinois, containing keys for identification of flowering plants and ferns. Notre Dame, Ind., University of Notre Dame Press, 1963. url p. 269.
• Flora of New Mexico / by E.O. Wooton and Paul C. Standley. Washington: G.P.O., 1915. url p. 749.
• Flora of New Mexico. By E.O. Wooton and Paul C. Standley. WashingtonGovt. Print. Off.1915 url p. 749.
• Flower gardening, New York, bMcBride, Nast & company, 1913. url , .
• Flower gardening, by H. S. Adams. New York, McBride, Nast & Company, 1913. url p. 203, p. 206.
• Fritz Bahr's commercial floriculture; a practical manual for the retail grower, New York, The A. T. De la Mare company, inc.[c1922] url .
• Hand-list of herbaceous plants cultivated in the Royal Botanic Gardens. London, Printed for H. M. Stationery Off. by Darling, 1902. url p. 263.
• Horticulture. Boston, Mass.: Horticulture Pub. Co., c1904-. url p. 155, p. 451.
• Journal kept by David Douglas during his travels in North America 1823-1827, together with a particular description of thirty-three species of American oaks and eighteen species of Pinus, with appendices containing a list of the plants introduced by Douglas and an account of h London, W. Wesley & Son, 1914. url , , p. 351.
• List of intercepted plant pests / United States Department of Agriculture, Plant Quarantine and Control Administration. [Washington, D.C.: U.S. G.P.O.], 1932- url p. 24.
• Loudon's encyclopaedia of plants; comprising the specific character, description, culture, history, application in the arts, and every other desirable particular respecting all the plants indigenous to, cultivated in, or introduced in Edited by Mrs. Loudon, assisted by George Don and David Wooster. London, Longmans, Green, 1866. url p. 1252.
• My garden, by Louise Beebe Wilder. .. illustrated by Will Simmons. Garden City, N. Y.: Doubleday, Page & company, [c1916] url p. 195, p. 195.
• Nicholson, G. The illustrated dictionary of gardening: a practical and scientific encyclopædia of horticulture for gardeners and botanists /edited by George Nicholson; assisted by J.W.H. Trail. .. and J. Garrett. .. 9 1884 London: L.U. Gill, [1884]-88. url p. 434.
• Phytologia. Bronx Park, New York, H.A. Gleason and H.N. Moldenke, url p. 129, p. 393, p. 395.
• Plant culture; a working hand-book of every day practice for all who grow flowering and ornamental plants in the garden and greenhouse, by George W. Oliver. New York, A. T. De La Mare Printing and Publishing Co., c1912. url , p. 178, p. 178.
• Plant culture; a working handbook of every day practice for all who grow flowering and ornamental plants in the garden and greenhouse, New York, A. T. De La Mare Co., Inc.[c1921] url .
• Plantae Lindheimerianae: an enumeration of F. Lindheimer's collection of Texan plants, with remarks and descriptions of new species, etc. / by George Engelmann and Asa Gray. 1907 Boston: Printed by Freeman and Bolles, 1845-[1907] url p. 209, p. 209.
• Proceedings of the Entomological Society of Washington. Washington, etc.: Entomological Society of Washington url p. 33, p. 428, p. 504.
• Standardized plant names; a catalogue of approved scientific and common names of plants in American commerce. Salem, Mass., 1923. url p. 153, p. 36, p. 73.
• The American florist: a weekly journal for the trade. Chicago: American Florist Company, [1885-1931] url .
• The American flower garden companion. New York, G. C. Thorburn, 1838. url p. 165.
• The American flower garden directory: Philadelphia, Carey and Hart, 1841. url p. 25.
• The Annals and magazine of natural history; zoology, botany, and geology being a continuation of the Annals combined with Loudon and Charlesworth's Magazine of Natural History. London, Taylor and Francis, Ltd. url p. 189.
• The Asa Gray bulletin. 1 1952 Ann Arbor, Mich. url , p. 287.
• The Florists' exchange: a weekly medium of interchange for florists, nurserymen, seedsmen and the trade in general. New York, N.Y.: [A.T. De la Mare Ptg. and Pub. Co., url p. 1058, p. 118, p. 1203.
• The Garden: an illustrated weekly journal of gardening in all its branches. London: [s.n., url , p. 206, p. 224, p. 8.
• The Gardener's magazine and register of rural & domestic improvement. London: Longman, Rees, Orome, Brown and Green, 1826-1844. url p. 212.
• The Gardeners' chronicle and agricultural gazette. London: published for the proprietors, 1844-1873. url , , p. 331.
• The Gardeners' chronicle: a weekly illustrated journal of horticulture and allied subjects. London: [Gardeners Chronicle], 1874-1955. url p. 309, p. 752.
• The Horticulturist and journal of rural art and rural taste. Albany, N.Y.: Luther Tucker, 1846-1875. url p. 200.
• The Magazine of horticulture, botany, and all useful discoveries and improvements in rural affairs. Boston: Hovey and Co., 1837- url p. 180, p. 278, p. 423.
• The Proceedings of the Iowa Academy of Science. Des moines, Iowa: The Academy, [1889-1987] url p. 62, p. 69.
• The University of Kansas science bulletin. 48 1969 [Lawrence]: University of Kansas, 1902-1996. url p. 576, p. 577.
• The book of hardy flowers; a simple and complete descriptive guide to the cultivation in gardens of the trees and shrubs, perennial and annual flowers, that are hardy, or are suitable for planting out-of-doors in summer in temp Ed. by H. H. Thomas. .. Beautifully illustrated with thirty-two direct color photographs by H. Essenhigh Corke and sixty-four half-tone plates. 1915 New York, Funk & Wagnalls company; [etc., etc.][1915] url p. 99.
• The complete garden, by Albert D. Taylor, assisted by Gordon D. Cooper. Illustrated with fifty full page cuts, four line charts, and nine coloured plates. Garden City, N.Y., Doubleday, Page, 1921. url p. 240, p. 240.
• The complete illustrated book of garden magic. Chicago, J.G. Ferguson Pub. Co.[1969] url p. 151.
• The florist and pomologist. London: "Journal of Horticulture" Office, 1863-1879. url p. 284, p. 289.
• The gardener's magazine and register of rural & domestic improvement. London: Longman, Rees, Orme, Brown and Green, 1826-1844. url p. 112.
• The native flowers and ferns of the United States in their botanical, horticultural and popular aspects. Series [I]-II. Boston, L. Prang, 1878-1880. url , p. 70, p. 71, p. 72.
• The standard cyclopedia of horticulture; a discussion, for the amateur, and the professional and commercial grower, of the kinds, characteristics and methods of cultivation of the species of plants grown in the regions of the United States a Illustrated with colored plates, four thousand engravings in the text, and ninety-six full-page cuts. New York, Macmillan, 1919 [c1914] url p. 3584, p. 713.
• Torrey, J. Report on the United States and Mexican boundary survey: made under the direction of the secretary of the Interior /by William H. Emory, major First Cavalry, and United States commissioner. Washington: C. Wendell, printer, 1857-59. url p. 103, p. 103.
• Torreya. Burlington, Vt., Torrey Botanical Club, 1901-1945. url p. 175.
• Transactions of the. .. annual meetings of the Kansas Academy of Science. Topeka, Kan.: Kansas Pub. House, 1883-1901. url p. 110.
• Yearbook of the United States Department of Agriculture. Washington: G.P.O., 1895-1923. url p. 608.
• Garcia-Jacas, N., A. Susanna, V. Mozaffarian, and R. Ilarslan. 2000. The natural delimitation of Centaurea (Asteraceae: Cardueae): ITS sequence analysis of the Centaurea jacea group. Pl. Syst. Evol. 223: 185199.
• Moore, R. J. 1972. Distribution of native and introduced knapweeds (Centaurea) in Canada and the United States. Rhodora 74: 331346.
• Roché, B. F. and C. T. Roché. 1991. Identification, introduction, distribution, ecology, and economics of Centaurea species. In: L. F. James et al., eds. 1991. Noxious Range Weeds. Boulder, San Francisco, and Oxford. Pp. 274291.
• Wagenitz, G. 1955. Pollenmorphologie und Systematik in der Gattung Centaurea L. s.l. Flora 142: 213279.

Notes

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 November 15, 2007:

• Missouri Botanical Garden, Missouri Botanical Garden
• School of Life Sciences, Arizona State University, Arizona State University Vascular Plant Herbarium
• The Swedish Museum of Natural History
• , Herbarium of Oskarshamn
• USDA PLANTS, USDA PLANTS Database
• University of Alabama Biodiversity and Systematics, Herbarium

Identifiers

• Biodiversity Heritage Library NamebankID: 3875153
• Catalogue of Life Accepted Name Code: Ast-22496
• Global Biodiversity Information Facility Taxonkey: 13749292
• Globally Unique Identifier: urn:lsid:ipni.org:names:189870-1
• GRIN Nomen Number: 9812
• Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 36951
• Natural Heritage Network Species Identifier: PDAST1Y010
• U.S.D.A. Plant Symbol: CEAM2
• Zipcode Zoo Species Identifier: 29307

Footnotes

1. 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]
2. Mean = 518.630 meters (1,701.542 feet), Standard Deviation = 500.280 based on 174 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]

©2004-2012 David Stang. All rights reserved.