Hieracium#Species

Hieracium or hawkweeds, like others in the family Asteraceae, mostly have yellow,{{cite web |url=http://www.botanical.com/botanical/mgmh/h/hawwee07.html |title=Hawkweed, Wood |access-date=2007-12-16 |author=Mrs M. Grieve |author-link=Maud Grieve |year=1933 |work=A Modern Herbal |publisher=botanical.com |archive-date=2008-05-10 |archive-url=https://web.archive.org/web/20080510181619/http://www.botanical.com/botanical/mgmh/h/hawwee07.html |url-status=live }}

tightly packed flower-heads of numerous small flowers

but, unlike daisies and sunflowers in the same family, they have not two kinds of florets but only strap-shaped (spatulate) florets, each one of which is a complete flower in itself, not lacking stamens,

and joined to the stem by leafy bracts. As in other members of the tribe Cichorieae, each ray corolla is tipped by 3 to 5 teeth.

Erect single, glabrous or hairy stems, sometimes branched away from the point of attachment, sometimes branched throughout.

The hairiness of hawkweeds can be very complex: from surfaces with scattered to crowded, tapered, whiplike, straight or curly, smooth to setae; "stellate-pubescent" or surfaces with scattered to crowded, dendritically branched (often called, but seldom truly, "stellate") hairs; and "stipitate-glandular" or surfaces with scattered to crowded gland-tipped hairs mostly. Surfaces of stems, leaves, peduncles, and phyllaries may be glabrous or may bear one, two, or all three of the types of hairs mentioned above.{{cite web |url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=115448 |title=Hieracium in Flora of North America |access-date=2007-12-16 |author=John L. Strother |work=FNA Vol. 19, 20 and 21 |publisher=efloras.org |pages=Page 219, 278, 279 |archive-date=2008-04-21 |archive-url=https://web.archive.org/web/20080421045557/http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=115448 |url-status=live }}

Like the other members of the Chicory tribe, hawkweeds contain a milky latex.

The large yellow underwing moth (Noctua pronuba) feeds on Hieracium species.

Hieracium species are native to Africa, Asia, Europe, North America,{{cite web |url=https://plants.usda.gov/java/profile?symbol=HIERA |title=PLANTS Profile for Hieracium L. |access-date=2007-12-18 |author=Natural Resources Conservation Service |author-link=Natural Resources Conservation Service |year=2007 |work=The PLANTS Database |publisher=USDA, Baton Rouge, LA 70874-4490 USA. |archive-date=2008-10-10 |archive-url=https://web.archive.org/web/20081010020343/http://plants.usda.gov/java/profile?symbol=HIERA |url-status=live }} Central America and South America.

{{main|List of Hieracium species}}

The classification of Hieracium into species is notoriously difficult. One reason is the apomictic reproduction (in which plants asexually produce seeds), which tends to produce a lot of minor geographical variation. Over 9000 species names have been published in Hieracium but some botanists regard many of those as synonyms of larger species.

• Hieracium lachenalii - Common hawkweed
• Hieracium attenboroughianum – Attenborough’s hawkweed
• Hieracium bakerianum
• Hieracium hethlandiae – Cliva Hill hawkweed
• Hieracium lepidulum Stenstr. ex Dahlst. – tussock hawkweed
• Hieracium lucidum Guss. – Sicilian sparviere
• Hieracium insolitum (Zahn) Üksip
• Hieracium villosum Jacq.

The list below is a selection of species that have been accepted by the USDA Natural Resources Conservation Service and Canada.[http://www.for.gov.bc.ca/hfp/publications/00230/Hawkweed%20key_PNW_R3-June06.pdf Key to Identification of Invasive and Native Hawkweeks (Hieracium spp.) in the Pacific Northwest] {{Webarchive|url=https://web.archive.org/web/20130515233942/http://www.for.gov.bc.ca/hfp/publications/00230/Hawkweed%20key_PNW_R3-June06.pdf |date=2013-05-15 }}, BC Ministry of Forests

A more complete list is given in the list of Hieracium species.

{{div col|colwidth=24em}}

• Hieracium albertinum – houndstongue hawkweed
• Hieracium albiflorum Hook. – white hawkweed
• Hieracium × alleghaniense Britt. (pro sp.)
• Hieracium argutum Nutt. – southern hawkweed
• Hieracium × atramentarium (Naegeli & Peter) Zahn ex Engl. (pro sp.)
• Hieracium atratum Fries – polar hawkweed
• Hieracium bolanderi Gray – Bolander's hawkweed
• Hieracium × brachiatum Berth. ex DC.
• Hieracium canadense Michx. – Canada hawkweed
• Hieracium carneum Greene – Huachuca hawkweed
• Hieracium × fassettii Lepage
• Hieracium fendleri Schultz-Bip. – yellow hawkweed
• Hieracium × fernaldii Lepage
• Hieracium × fuscatrum Naegeli & Peter (pro sp.)
• Hieracium glomeratum Froel. – queen-devil hawkweed
• Hieracium gracile Hook. – slender hawkweed
• Hieracium greenei Gray – Greene's hawkweed
• Hieracium greenii Porter & Britt. – Maryland hawkweed
• Hieracium × grohii Lepage
• Hieracium gronovii L. – queendevil
• Hieracium horridum Fries – prickly hawkweed
• Hieracium kalmii L. – Kalm's hawkweed
• Hieracium lachenalii K.C. Gmel. – common hawkweed
• Hieracium laevigatum Willd. – smooth hawkweed
• Hieracium lemmonii Gray – Lemmon's hawkweed
• Hieracium longiberbe T.J. Howell – longbeard hawkweed
• Hieracium longipilum Torr. – hairy hawkweed
• Hieracium maculatum Sm. – spotted hawkweed
• Hieracium marianum Willd. – Maryland hawkweed
• Hieracium megacephalum Nash – coastal plain hawkweed
• Hieracium murorum L. – wall hawkweed
• Hieracium paniculatum L. – Allegheny hawkweed
• Hieracium parryi Zahn in H.G.A. Engler – Parry hawkweed
• Hieracium piloselloides Vill. – tall hawkweed
• Hieracium praealtum Vill. ex Gochnat – kingdevil
• Hieracium pringlei Gray – Pringle's hawkweed
• Hieracium robinsonii (Zahn) Fern. – Robinson's hawkweed
• Hieracium rusbyi Greene – Rusby's hawkweed
• Hieracium sabaudum L. – New England hawkweed
• Hieracium scabrum Michx. – rough hawkweed
• Hieracium schultzii Fries – roughstem hawkweed
• Hieracium scouleri Hook. – Scouler's woollyweed
• Hieracium scribneri Small – Scribner's hawkweed
• Hieracium traillii – Maryland hawkweed
• Hieracium triste Willd. ex Spreng. – woolly hawkweed
• Hieracium umbellatum L. – narrowleaf hawkweed
• Hieracium venosum L. – rattlesnakeweed

{{div col end}}

Some species are now placed in the genus Pilosella:{{Cite POWO|title=Pilosella Hill|id=30065694-2|access-date=2023-06-13|mode=cs1}}

• Hieracium aurantiacum L., syn. of Pilosella aurantiaca – orange hawkweed
• Hieracium caespitosum Dumort., syn. of Pilosella caespitosa – meadow hawkweed
• Hieracium flagellare Willd., syn. of Pilosella flagellaris – whiplash hawkweed
• Hieracium floribundum Wimmer & Grab., syn. of Pilosella floribunda – kingdevil hawkweed
• Hieracium lactucella Wallr., syn. of Pilosella lactucella – European hawkweed
• Hieracium pilosella L., syn. of Pilosella officinarum – mouse-ear hawkweed

All species of the genus Hieracium are classed as invasive species throughout New Zealand. They are banned from sale, propagation and distribution under the National Pest Plant Accord. Hieracium is a pasture weed that reduces available feed for livestock and displaces the indigenous plants.{{cite web |url=http://www.weedbusters.co.nz/weed_info/detail.asp?WeedID=119 |title=Hieracium species Detailed information sheet |publisher=The Weedbusters Management Committee (www.weedbusters.co.nz) |access-date=2010-05-02 |url-status=dead |archive-url=https://web.archive.org/web/20100515032635/http://weedbusters.co.nz/weed_info/detail.asp?WeedID=119 |archive-date=2010-05-15}} It is a particular threat in alpine ecosystems previously dominated by native tussocks, though it will colonise habitats from bare ground, to exotic pine forest, to native Southern Beech forest.{{cite web |url=http://www.doc.govt.nz/documents/science-and-technical/DSIS109.pdf |title=Genetic diversity in tussock hawkweed (Hieracium lepidulum) and use of allele frequencies for identifying patterns of spread |access-date=2013-09-06 |archive-date=2016-03-05 |archive-url=https://web.archive.org/web/20160305035152/http://www.doc.govt.nz/documents/science-and-technical/DSIS109.pdf |url-status=live }}

In the United States, many species of Hieracium have been introduced and all species present are considered noxious weeds in one or more states.{{cite web |url=http://plants.usda.gov/plant-profile?symbol=HIERA |title=Hieracium L._hawkweed_USDA NRCS |access-date=2013-09-06 |archive-date=2014-04-24 |archive-url=https://web.archive.org/web/20140424233413/http://plants.usda.gov/core/profile?symbol=HIERA |url-status=live }}

In Australia, hawkweeds are invasive pests in alpine regions, all species of Hieracium are listed or declared under various State Acts.{{Cite web |url=http://invasives.org.au/blog/hawkweeds-a-recent-discovery-in-victorias-alps-and-a-taxonomic-name-change/ |title=Hawkweeds: A recent discovery in Victoria's Alps and a taxonomic name change |date=10 July 2013 |access-date=6 March 2016 |archive-date=5 March 2016 |archive-url=https://web.archive.org/web/20160305132142/http://invasives.org.au/blog/hawkweeds-a-recent-discovery-in-victorias-alps-and-a-taxonomic-name-change/ |url-status=live }}

{{Reflist}}

• {{cite book |last=Espie |first=Peter |title=Hieracium in New Zealand: ecology and management |publisher=AgResearch |location=Mosgiel |year=2001 |isbn=0-478-20900-2}}
• McCosh, D. and Rich, T.C.G. 209. Hieracium proximum (Caithness Hawkweed) in Ireland. Ir. Nat J. 30: 54.
• Rich, T.C.G., Cotton, D.C.F., Hood, R.L.I.B., Houston, L., McCosh, J. and Jackson, M.B.W. 2009. Conservation of Ireland's biodiversity: status of the Irish endemic Hieracium basalticola Pugsley (Basalt Hawkweed) (Asteraceae). Ir. Nat J. 30: 79–89.

• {{cite web |url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=37691 |title=Standard Report Hieracium |access-date=2007-12-18 |author=Integrated Taxonomic Information System (ITIS) |author-link=Integrated Taxonomic Information System}}
• {{cite web |url=http://www.globaltwitcher.com/taxa_genus.asp?genusid=5148 |title=Hieracium on GlobalTwitcher.com |access-date=2008-06-15 |author=Nicklas Strömberg |work=Images on Hieracium found in Sweden |publisher=GlobalTwitcher.com |url-status=dead |archive-url=https://web.archive.org/web/20110711101752/http://www.globaltwitcher.com/taxa_genus.asp?genusid=5148 |archive-date=2011-07-11}}
• {{cite web |url=http://aob.oxfordjournals.org/cgi/content/abstract/100/6/1323 |archive-url=https://web.archive.org/web/20080907032858/http://aob.oxfordjournals.org/cgi/content/abstract/100/6/1323 |url-status=dead |archive-date=7 September 2008 |title=Genome Size Variation and Species Relationships in Hieracium Sub-genus Pilosella (Asteraceae) as Inferred by Flow Cytometry |access-date=2007-12-16 |author1=Jan Suda |author2=Anna Krahulcová |author3=Pavel Trávnícek |author4=Radka Rosenbaumová |author5=Tomás Peckert |author6=Frantisek Krahulec |date=7 October 2007 |work=Annals of Botany |publisher=Oxford Journals}}
• {{cite web |url=http://www.ag.uidaho.edu/hawkweed/ |title=Hawkweeds |access-date=2007-12-16 |publisher=University of Idaho |location=Moscow, ID |work=Hawkweed Identification, Management and Research |url-status=dead |archive-url=https://web.archive.org/web/20071020044249/http://www.ag.uidaho.edu/hawkweed/ |archive-date=2007-10-20}}
• {{cite web |url=http://www.agf.gov.bc.ca/cropprot/weedguid/orangehw.htm |title=Orange Hawkweed (Hieracium aurantiacum) |access-date=2007-12-16 |author=British Columbia Ministry of Agriculture and Lands |author-link=List of British Columbia Government Agencies and Crown Corporations |work=Field Guide to Noxious and Other Selected Weeds of British Columbia}}
• {{cite web |url=http://www.tussocks.net.nz/hieracium/ |title=Hieracium Management Gateway |publisher=Tussock Grassland Management Information System |access-date=2009-01-12 |url-status=dead |archive-url=https://web.archive.org/web/20081014045929/http://www.tussocks.net.nz/hieracium/ |archive-date=2008-10-14}}

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Category:Asteraceae genera

Category:Taxa named by Carl Linnaeus