Centaurea nigra (common knapweed, lesser knapweed, hardheads)

Interactions where Centaurea nigra is the victim or passive partner (and generally loses out from the process)

The following relationships have been collated from the published literature (see 'References').

Filters:

Affected Part	Summary	Taxon	Vernacular	Classification	References	Darwin Classification of Active Taxon	Active Taxon	Active Vernacular	Active State	Active Part	Active Stage	Relationship	Relationship Geography	Darwin Classification of Passive Taxon	Passive Taxon	Passive Vernacular	Passive Taxon Uncertain	Passive State	Passive Part	Passive Taxon's significance to Active Taxon	Season	Summary
	is foodplant of larva	Campiglossa misella	a gall fly	Diptera: Tephritidae	Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Campiglossa misella/	Campiglossa misella	a gall fly			larva	Foodplant / feeds on		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads	?					larva feeds on
	has sap sucked by adult	Eurygaster maura	European Tortoise Bug	Hemiptera: Scutelleridae	Land and Water Bugs of the British Isles, Southwood, T.R.E. & Leston, D., 1959	/Animalia/Arthropoda/Insecta/Hemiptera/Scutelleridae/Eurygaster maura/	Eurygaster maura	european tortoise bug			adult	Foodplant / sap sucker	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads				Minor		adult sucks sap of
	has sap sucked by nymph	Eurygaster maura	European Tortoise Bug	Hemiptera: Scutelleridae	Land and Water Bugs of the British Isles, Southwood, T.R.E. & Leston, D., 1959	/Animalia/Arthropoda/Insecta/Hemiptera/Scutelleridae/Eurygaster maura/	Eurygaster maura	european tortoise bug			nymph	Foodplant / sap sucker	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads				Minor		nymph sucks sap of
	is parasitised by pycnium	Puccinia hieracii var hieracii	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia hieracii var. hieracii/	Puccinia hieracii var. hieracii	a rust fungus			pycnium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads				Minor		pycnium parasitises
	is parasitised by aecium	Puccinia hieracii var hieracii	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia hieracii var. hieracii/	Puccinia hieracii var. hieracii	a rust fungus			aecium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads				Minor		aecium parasitises
(live)	live is parasitised by	Golovinomyces cichoracearum	a powdery mildew	Erysiphales: Erysiphaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 An Introduction to British Powdery Mildews, Ing, B., 1990	/Fungi/Ascomycota/Leotiomycetes/Erysiphales/Erysiphaceae/Golovinomyces cichoracearum/	Golovinomyces cichoracearum	a powdery mildew				Foodplant / parasite	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live		Major		parasitises live
(live)	live is parasitised by pycnium	Puccinia calcitrapae	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia calcitrapae/	Puccinia calcitrapae	a rust fungus			pycnium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live		Major		pycnium parasitises live
(live)	live is parasitised by aecium	Puccinia dioicae var arenariicola	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia dioicae var. arenariicola/	Puccinia dioicae var. arenariicola	a rust fungus			aecium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live				aecium parasitises live
(live)	live is parasitised by pycnium	Puccinia dioicae var arenariicola	a rust fungus	Pucciniales: Pucciniaceae	Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia dioicae var. arenariicola/	Puccinia dioicae var. arenariicola	a rust fungus			pycnium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live				pycnium parasitises live
achene	achene is galled by larva	Urophora jaceana	Knapweed Gall-fly	Diptera: Tephritidae	Plant Galls, Redfern, M. & Askew, R.R., 1992 Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Urophora jaceana/	Urophora jaceana	knapweed gall-fly			larva	Foodplant / gall	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			achene	Major	(-9)	larva causes gall of achene
capitulum?	capitulum? may contain larva	Acinia corniculata	Scarce Knapweed Fly	Diptera: Tephritidae	Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Acinia corniculata/	Acinia corniculata	scarce knapweed fly			larva	Foodplant / internal feeder	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads	?		capitulum?			larva feeds within capitulum?
capitulum	capitulum may contain larva	Chaetorellia jaceae	Lesser Golden Knapweed Fly	Diptera: Tephritidae	Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Chaetorellia jaceae/	Chaetorellia jaceae	lesser golden knapweed fly			larva	Foodplant / internal feeder	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			capitulum	Major		larva feeds within capitulum
capitulum	capitulum may contain larva	Chaetostomella cylindrica	a gall fly	Diptera: Tephritidae	Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Chaetostomella cylindrica/	Chaetostomella cylindrica	a gall fly			larva	Foodplant / internal feeder	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			capitulum	Major		larva feeds within capitulum
capitulum	capitulum is galled by larva	Urophora quadrifasciata	Four-banded Knapweed Gall-fly	Diptera: Tephritidae	Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Urophora quadrifasciata/	Urophora quadrifasciata	four-banded knapweed gall-fly			larva	Foodplant / gall	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			capitulum	Major		larva causes gall of capitulum
capitulum	capitulum may contain larva	Xyphosia miliaria	Mottled Thistle Fly	Diptera: Tephritidae	Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Xyphosia miliaria/	Xyphosia miliaria	mottled thistle fly			larva	Foodplant / internal feeder	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			capitulum	Rare		larva feeds within capitulum
capitulum	capitulum has sap sucked by nymph	Oncotylus viridiflavus	a plantbug or grassbug	Hemiptera: Miridae	Land and Water Bugs of the British Isles, Southwood, T.R.E. & Leston, D., 1959	/Animalia/Arthropoda/Insecta/Hemiptera/Miridae/Oncotylus (Oncotylus) viridiflavus/	Oncotylus (Oncotylus) viridiflavus	a plantbug or grassbug			nymph	Foodplant / sap sucker		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			capitulum			nymph sucks sap of capitulum
capitulum	capitulum has sap sucked by adult	Oncotylus viridiflavus	a plantbug or grassbug	Hemiptera: Miridae	Land and Water Bugs of the British Isles, Southwood, T.R.E. & Leston, D., 1959	/Animalia/Arthropoda/Insecta/Hemiptera/Miridae/Oncotylus (Oncotylus) viridiflavus/	Oncotylus (Oncotylus) viridiflavus	a plantbug or grassbug			adult	Foodplant / sap sucker		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			capitulum			adult sucks sap of capitulum
capitulum (live)	live capitulum may contain larva	Acanthiophilus helianthi	Knapweed Ghost	Diptera: Tephritidae	Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Acanthiophilus helianthi/	Acanthiophilus helianthi	knapweed ghost			larva	Foodplant / internal feeder	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	capitulum	Sole		larva feeds within live capitulum
capitulum (live)	live capitulum is galled by larva	Isocolus jaceae	a gall wasp	Hymenoptera: Cynipidae	Catalogue of parasitoids and inquilines in galls of Aylacini, Diplolepidini and Pediaspidini (Hym., Cynipidae) in the West Palaearctic, Askew, R.R., Plantard, O., Gomez, J.F., Nieves, M.H. & Nieves-Aldrey, J.L., 2006	/Animalia/Arthropoda/Insecta/Hymenoptera/Cynipidae/Isocolus jaceae/	Isocolus jaceae	a gall wasp			larva	Foodplant / gall		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	capitulum			larva causes gall of live capitulum
leaf-mine	leaf-mine may house puparium	Phytomyza autumnalis	a leaf-mining fly	Diptera: Agromyzidae	Diptera: Agromyzidae, Spencer, K.A., 1972	/Animalia/Arthropoda/Insecta/Diptera/Agromyzidae/Phytomyza autumnalis/	Phytomyza autumnalis	a leaf-mining fly			puparium	Plant / resting place / within		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			leaf-mine			puparium may be found in leaf-mine
leaf	leaf is mined by larva	Liriomyza centaureae	a leaf-mining fly	Diptera: Agromyzidae	Diptera: Agromyzidae, Spencer, K.A., 1972	/Animalia/Arthropoda/Insecta/Diptera/Agromyzidae/Liriomyza centaureae/	Liriomyza centaureae	a leaf-mining fly			larva	Foodplant / miner		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			leaf	Sole		larva mines leaf
leaf	leaf is mined by larva	Phytomyza autumnalis	a leaf-mining fly	Diptera: Agromyzidae	Diptera: Agromyzidae, Spencer, K.A., 1972	/Animalia/Arthropoda/Insecta/Diptera/Agromyzidae/Phytomyza autumnalis/	Phytomyza autumnalis	a leaf-mining fly			larva	Foodplant / miner		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			leaf			larva mines leaf
leaf (fading)	fading leaf has leaves shot holed by punctiform pycnidium of Septoria coelomycetous anamorph	Septoria centaureae	a coelomycete	Capnodiales: Mycosphaerellaceae	Fungi of the South East England, Dennis, R.W.G., 1995 British Stem- and Leaf- Fungi: Coelomycetes Vol. I … Sphaeropsidales with hyaline conidia, Grove, W.B., 1935	/Fungi/Ascomycota/Dothideomycetes/Capnodiales/Mycosphaerellaceae/Septoria centaureae/	Septoria centaureae	a coelomycete	punctiform	pycnidium	Septoria coelomycetous anamorph	Foodplant / shot hole causer	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		fading	leaf		(8-9)	punctiform pycnidium of Septoria coelomycetous anamorph causes shot holes on fading leaf
leaf (fading)	fading leaf is spotted by punctiform pycnidium of Septoria coelomycetous anamorph	Septoria centaureae	a coelomycete	Capnodiales: Mycosphaerellaceae	Fungi of the South East England, Dennis, R.W.G., 1995 British Stem- and Leaf- Fungi: Coelomycetes Vol. I … Sphaeropsidales with hyaline conidia, Grove, W.B., 1935	/Fungi/Ascomycota/Dothideomycetes/Capnodiales/Mycosphaerellaceae/Septoria centaureae/	Septoria centaureae	a coelomycete	punctiform	pycnidium	Septoria coelomycetous anamorph	Foodplant / spot causer	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		fading	leaf		(8-9)	punctiform pycnidium of Septoria coelomycetous anamorph causes spots on fading leaf
leaf (live)	live leaf is parasitised by sporangium	Bremia lactucae	Lettuce Downy Mildew	Peronosporales: Peronosporaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 New British hosts for the downy mildew Bremia lactucae, Legon, N. & Spooner, B., 2015 A Checklist of the Downy Mildews (Peronosporaceae) of the British Isles, Preece, T.F., 2002	/Chromista/Oomycota/Peronosporea/Peronosporales/Peronosporaceae/Bremia lactucae/	Bremia lactucae	lettuce downy mildew			sporangium	Foodplant / parasite	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	leaf	Minor	(9-10)	sporangium parasitises live leaf
leaf (live)	live leaf is spotted by usually hypophyllous colony of Ramularia anamorph	Ramularia triboutiana	an anamorphic fungus	Capnodiales: Mycosphaerellaceae	Monograph of Cercosporella, Ramularia and Allied Genera - Vol II, Braun, U., 1998 Fungi of the South East England, Dennis, R.W.G., 1995 Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997	/Fungi/Ascomycota/Dothideomycetes/Capnodiales/Mycosphaerellaceae/Ramularia triboutiana/	Ramularia triboutiana	an anamorphic fungus	usually hypophyllous	colony	Ramularia anamorph	Foodplant / spot causer	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	leaf			usually hypophyllous colony of Ramularia anamorph causes spots on live leaf
leaf (live)	live leaf is parasitised by uredinoid, mostly epiphyllous aecium	Puccinia calcitrapae	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia calcitrapae/	Puccinia calcitrapae	a rust fungus	uredinoid, mostly epiphyllous		aecium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	leaf	Major		uredinoid, mostly epiphyllous aecium parasitises live leaf
leaf (live)	live leaf is parasitised by mostly hypophyllous telium	Puccinia calcitrapae	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia calcitrapae/	Puccinia calcitrapae	a rust fungus	mostly hypophyllous		telium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	leaf	Major		mostly hypophyllous telium parasitises live leaf
leaf (live)	live leaf is parasitised by mostly hypophyllous uredium	Puccinia calcitrapae	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia calcitrapae/	Puccinia calcitrapae	a rust fungus	mostly hypophyllous		uredium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	leaf	Major		mostly hypophyllous uredium parasitises live leaf
leaf (live)	live leaf is parasitised by uredium	Puccinia hieracii var hieracii	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia hieracii var. hieracii/	Puccinia hieracii var. hieracii	a rust fungus			uredium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	leaf	Minor		uredium parasitises live leaf
receptacle	receptacle is galled by larva	Urophora jaceana	Knapweed Gall-fly	Diptera: Tephritidae	Plant Galls, Redfern, M. & Askew, R.R., 1992 Tephritid Flies (Diptera: Tephritidae), White, I.M., 1988	/Animalia/Arthropoda/Insecta/Diptera/Tephritidae/Urophora jaceana/	Urophora jaceana	knapweed gall-fly			larva	Foodplant / gall	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			receptacle	Major	(-9)	larva causes gall of receptacle
stem	stem may contain larva	Melanagromyza dettmeri	a leaf-mining fly	Diptera: Agromyzidae	Diptera: Agromyzidae, Spencer, K.A., 1972 The Agromyzidae (Diptera) of Fennoscandia and Denmark, Spencer, K.A., 1976	/Animalia/Arthropoda/Insecta/Diptera/Agromyzidae/Melanagromyza dettmeri/	Melanagromyza dettmeri	a leaf-mining fly			larva	Foodplant / internal feeder		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			stem			larva feeds within stem
stem	stem may house puparium	Melanagromyza dettmeri	a leaf-mining fly	Diptera: Agromyzidae	Diptera: Agromyzidae, Spencer, K.A., 1972	/Animalia/Arthropoda/Insecta/Diptera/Agromyzidae/Melanagromyza dettmeri/	Melanagromyza dettmeri	a leaf-mining fly			puparium	Plant / resting place / within		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			stem			puparium may be found in stem
stem	stem may contain larva	Napomyza hirticornis	a leaf-mining fly	Diptera: Agromyzidae	Diptera: Agromyzidae, Spencer, K.A., 1972	/Animalia/Arthropoda/Insecta/Diptera/Agromyzidae/Napomyza hirticornis/	Napomyza hirticornis	a leaf-mining fly			larva	Foodplant / internal feeder		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads			stem			larva feeds within stem
stem (dead, decayed)	dead, decayed stem is decayed by fruitbody	Subulicystidium longisporum	a resupinate fungus	Trechisporales: Hydnodontaceae	Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Agaricomycetes/Trechisporales/Hydnodontaceae/Subulicystidium longisporum/	Subulicystidium longisporum	a resupinate fungus			fruitbody	Foodplant / saprobe		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead, decayed	stem	Minor		fruitbody is saprobic on dead, decayed stem
stem (dead, fallen, covered by grass)	dead, fallen, covered by grass stem is decayed by stalked apothecium	Hymenoscyphus limonium	a discomycete	Helotiales: Helotiaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997	/Fungi/Ascomycota/Leotiomycetes/Helotiales/Helotiaceae/Hymenoscyphus limonium/	Hymenoscyphus limonium	a discomycete	stalked		apothecium	Foodplant / saprobe		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead, fallen, covered by grass	stem	Major	(10-11)	stalked apothecium is saprobic on dead, fallen, covered by grass stem
stem (dead, silvery-grey-spotted)	dead, silvery-grey-spotted stem is decayed by gregarious, black pycnidium of Rhabdospora coelomycetous anamorph	Rhabdospora coriacea	a coelomycete	Capnodiales: Mycosphaerellaceae	British Stem- and Leaf- Fungi: Coelomycetes Vol. I … Sphaeropsidales with hyaline conidia, Grove, W.B., 1935	/Fungi/Ascomycota/Dothideomycetes/Capnodiales/Mycosphaerellaceae/Rhabdospora coriacea/	Rhabdospora coriacea	a coelomycete	gregarious, black	pycnidium	Rhabdospora coelomycetous anamorph	Foodplant / saprobe	UK and/or Eire	/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead, silvery-grey-spotted	stem			gregarious, black pycnidium of Rhabdospora coelomycetous anamorph is saprobic on dead, silvery-grey-spotted stem
stem (dead)	dead stem is decayed by immersed pseudothecium	Kalmusia clivensis	an ascomycete	Pleosporales: Montagnulaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997	/Fungi/Ascomycota/Dothideomycetes/Pleosporales/Montagnulaceae/Kalmusia clivensis/	Kalmusia clivensis	an ascomycete	immersed		pseudothecium	Foodplant / saprobe		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead	stem		(5-6)	immersed pseudothecium is saprobic on dead stem
stem (dead)	dead stem is decayed by sessile apothecium	Mollisia coerulans	a discomycete	Helotiales: Dermateaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997	/Fungi/Ascomycota/Leotiomycetes/Helotiales/Dermateaceae/Mollisia coerulans/	Mollisia coerulans	a discomycete	sessile		apothecium	Foodplant / saprobe		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead	stem	Minor	(4-6)	sessile apothecium is saprobic on dead stem
stem (dead)	dead stem is decayed by erumpent apothecium	Pyrenopeziza adenostylidis	a discomycete	Helotiales: Dermateaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997	/Fungi/Ascomycota/Leotiomycetes/Helotiales/Dermateaceae/Pyrenopeziza adenostylidis/	Pyrenopeziza adenostylidis	a discomycete	erumpent		apothecium	Foodplant / saprobe		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead	stem		(5-11)	erumpent apothecium is saprobic on dead stem
stem (dead)	dead stem is decayed by sessile apothecium	Unguicularia incarnatina	a discomycete	Helotiales: Hyaloscyphaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997	/Fungi/Ascomycota/Leotiomycetes/Helotiales/Hyaloscyphaceae/Unguicularia incarnatina/	Unguicularia incarnatina	a discomycete	sessile		apothecium	Foodplant / saprobe		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead	stem		(4-7)	sessile apothecium is saprobic on dead stem
stem (dead)	dead stem is decayed by effuse colony of Phragmocephala dematiaceous anamorph	Phragmocephala elliptica	a dematiaceous anamorphic fungus		Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997	/Fungi/Ascomycota/Phragmocephala elliptica/	Phragmocephala elliptica	a dematiaceous anamorphic fungus	effuse	colony	Phragmocephala dematiaceous anamorph	Foodplant / saprobe		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead	stem		(4-10)	effuse colony of Phragmocephala dematiaceous anamorph is saprobic on dead stem
stem (dead)	dead stem is decayed by colony of Stachybotrys dematiaceous anamorph	Stachybotrys dichroa	a dematiaceous anamorphic fungus	Hypocreales: Stachybotryaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997	/Fungi/Ascomycota/Sordariomycetes/Hypocreales/Stachybotryaceae/Stachybotrys dichroa/	Stachybotrys dichroa	a dematiaceous anamorphic fungus		colony	Stachybotrys dematiaceous anamorph	Foodplant / saprobe		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		dead	stem		(4-9)	colony of Stachybotrys dematiaceous anamorph is saprobic on dead stem
stem (live)	live stem is galled by larva	Isocolus scabiosae	a gall wasp	Hymenoptera: Cynipidae	Hymenoptera - Cynipoidea, Key to families and subfamilies and Cynipinae (including galls), Eady R.D. & Quinlan, J., 1963	/Animalia/Arthropoda/Insecta/Hymenoptera/Cynipidae/Isocolus scabiosae/	Isocolus scabiosae	a gall wasp			larva	Foodplant / gall		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	stem			larva causes gall of live stem
stem (live)	live stem is galled by larva	Phanacis centaureae	a gall wasp	Hymenoptera: Cynipidae	Catalogue of parasitoids and inquilines in galls of Aylacini, Diplolepidini and Pediaspidini (Hym., Cynipidae) in the West Palaearctic, Askew, R.R., Plantard, O., Gomez, J.F., Nieves, M.H. & Nieves-Aldrey, J.L., 2006	/Animalia/Arthropoda/Insecta/Hymenoptera/Cynipidae/Phanacis centaureae/	Phanacis centaureae	a gall wasp			larva	Foodplant / gall		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	stem			larva causes gall of live stem
stem (live)	live stem is parasitised by uredium	Puccinia hieracii var hieracii	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia hieracii var. hieracii/	Puccinia hieracii var. hieracii	a rust fungus			uredium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	stem	Minor		uredium parasitises live stem
stem (live)	live stem is parasitised by telium	Puccinia hieracii var hieracii	a rust fungus	Pucciniales: Pucciniaceae	Microfungi on Land Plants: An Identification Handbook, Ellis, M.B. & J.P., 1997 Checklist of the British and Irish Basidiomycota, Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	/Fungi/Basidiomycota/Pucciniomycetes/Pucciniales/Pucciniaceae/Puccinia hieracii var. hieracii/	Puccinia hieracii var. hieracii	a rust fungus			telium	Foodplant / parasite		/Plantae/Tracheophyta/Magnoliopsida/Asterales/Asteraceae/Centaurea nigra/	Centaurea nigra	common knapweed, lesser knapweed, hardheads		live	stem	Minor		telium parasitises live stem

Species	Centaurea nigra (Common Knapweed, Lesser Knapweed, Hardheads)
Genus	Centaurea (knapweeds and star-thistles)
Tribe	Cardueae (“thistles”)
Subfamily	LACTUCOIDEAE (“dandelions”)
Family	ASTERACEAE (daisies, dandelions and thistles, composite)
Order	ASTERALES (daisies, dandelions, thistles and bell flowers)
Subclass	EU-DICOTS (dicotyledonous flowering plants)
Class	MAGNOLIOPSIDA (flowering plants)
Phylum	TRACHEOPHYTA (vascular plants)
Kingdom	PLANTAE (plants)
Domain	Eukaryota (eukaryotes)
Life	BIOTA (living things)

Centaurea nigra L.
(Common Knapweed, Lesser Knapweed, Hardheads)

Interactions where Centaurea nigra is the victim or passive partner (and generally loses out from the process)

Taxonomic hierarchy:

Centaurea nigra is also a member of:

BioInfo - Wildlife Information (UK)

Author & Year	Title	Source
Askew, R.R., Plantard, O., Gomez, J.F., Nieves, M.H. & Nieves-Aldrey, J.L., 2006	Catalogue of parasitoids and inquilines in galls of Aylacini, Diplolepidini and Pediaspidini (Hym., Cynipidae) in the West Palaearctic	Zootaxa 1301.
Braun, U., 1998	Monograph of Cercosporella, Ramularia and Allied Genera - Vol II	Phytopathogenic Hyphomycetes, 2, 493pp, IHW-Verlag
Dennis, R.W.G., 1995	Fungi of the South East England	383pp, Royal Botanic Gardens, Kew
Eady R.D. & Quinlan, J., 1963	Hymenoptera - Cynipoidea, Key to families and subfamilies and Cynipinae (including galls)	Handbooks for the Identification of British Insects , Vol VIII, Part 1 (a), 81pp, The Royal Entomological Society of London
Ellis, M.B. & J.P., 1997	Microfungi on Land Plants: An Identification Handbook	2nd (New Enlarged) edition, 868pp, The Richmond Publishing Co. Ltd
Grove, W.B., 1935	British Stem- and Leaf- Fungi: Coelomycetes Vol. I … Sphaeropsidales with hyaline conidia	Vol I, 488pp, Cambridge University Press
Ing, B., 1990	An Introduction to British Powdery Mildews	Mycologist Vol 4 (1) et seq.
Legon, N. & Spooner, B., 2015	New British hosts for the downy mildew Bremia lactucae	Field Mycology Vol 16 (1): 29-32.
Legon, N.W. & Henrici, A. with Roberts, P.J., Spooner, B.M. & Watling, R., 2005	Checklist of the British and Irish Basidiomycota	517pp, Royal Botanic Gardens, Kew
Preece, T.F., 2002	A Checklist of the Downy Mildews (Peronosporaceae) of the British Isles	33pp, British Mycological Society
Redfern, M. & Askew, R.R., 1992	Plant Galls	Naturalists’ Handbooks, No 17, 99pp, The Richmond Publishing Co. Ltd
Southwood, T.R.E. & Leston, D., 1959	Land and Water Bugs of the British Isles	Wayside & Woodland Series, 1959 edition, 436pp, Frederick Warne & Co. Ltd.
Spencer, K.A., 1972	Diptera: Agromyzidae	Handbooks for the Identification of British Insects , Vol X. Part 5(g), 136pp, The Royal Entomological Society of London
Spencer, K.A., 1976	The Agromyzidae (Diptera) of Fennoscandia and Denmark	Fauna Entomologica Scandinavica, 5 (parts 1 and 2), 606pp, Scandinavian Science Press
White, I.M., 1988	Tephritid Flies (Diptera: Tephritidae)	Handbooks for the Identification of British Insects , Vol 10. Part 5a, 134pp, The Royal Entomological Society of London