{"id":"corylus-avellana-contorted","license":"CC-BY-4.0","data":{"scientificName":"Corylus avellana 'Contorted'","commonNames":["Contorted filbert"],"taxonRank":"species","acceptedName":"Corylus avellana","family":"Betulaceae","ids":{"usdaSymbol":"COAV80","gbifKey":2875979,"itisTsn":501642,"wikidataQid":"Q124969","inatTaxonId":54491},"usdaZoneMin":"5a","zoneSource":"fps-2016","states":["DC","DE","MD","NJ","NY","OH","OR","PA","WA","WV"],"statusAssertions":[{"status":"introduced-established","channel":"ecological","geography":{"grain":"aggregate-region","regions":["L48"]},"source":"us-riis-v2","sourceRecordId":"USRIIS-L48-Plantae7314","sourceVersion":"2.0 (November 2022)","asOf":"2022-10-23T00:00:00.000Z","sourceModified":"2017-11-21T00:00:00.000Z","sourceTaxon":{"name":"Corylus avellana","rank":"species","rawRank":"Species"},"sourceDesignation":{"code":"C3","label":"established (category C3)"},"associatedReferences":["USDA Natural Resources Conservation Service (NRCS) PLANTS Database (2021ang), https://plants.usda.gov/home/plantProfile?symbol=COAV80"],"taxonProjection":{"basis":"accepted-name","notes":"exact source identifier, rank, family, and scientific/accepted name"}}],"hardinessAssertions":[{"minimum":"5","interpretation":"ambiguous-single-value","precision":"whole-zone","zoneMapping":"source-stated","applicability":"uncertain","applicabilityNotes":"The recovered selector prints one Cold Hardiness Zone value but does not define it as a minimum threshold or a one-zone range.","source":"fps-eastern-us","sourceRecordId":"corylus-avellana-contorted","sourceTaxon":"Corylus avellana 'Contorted'","taxonMatch":"exact","sourcePlacement":"Cold Hardiness Zone field in the recovered selector record","sourceVersion":"2016-wayback","asOf":"2026-08-26T00:00:00.000Z"},{"minimum":"4","maximum":"8","interpretation":"explicit-range","precision":"whole-zone","zoneMapping":"source-stated","applicability":"applicable","source":"msu-e2948","sourceRecordId":"shrub:Corylus avellana","sourceTaxon":"Corylus avellana","taxonMatch":"accepted-name","sourcePlacement":"Table 1, shrub row","sourceVersion":"New, January 2007","asOf":"2026-08-26T00:00:00.000Z"}],"plantForm":"shrub","matureHeightFt":6,"sun":"full","photo":{"file":"/images/plants/corylus-avellana-contorted.jpg","sourceUrl":"https://www.inaturalist.org/photos/31532077","observationUrl":"https://www.inaturalist.org/observations/20421636","license":"cc0","attribution":"no rights reserved","fetchedOn":"2026-08-23T00:00:00.000Z"},"evidence":[{"source":"fps-eastern-us","verdict":"mixed","verdictRaw":"AT RISK Firewise (3)","claims":"Twisted branches used in landscapes. It is grafted for landscape use. Suckers coming from roots must be kept removed.","sourcePlacement":{"value":"LZ2","scheme":"fps-landscape-zone"},"edition":"2016-wayback","accessedOn":"2026-08-23T00:00:00.000Z"},{"source":"osu-b921","verdict":"recommend","verdictRaw":"L flammability","claims":"Prized for its nut production; adapts to various soils.","edition":"2006","url":"http://web.archive.org/web/20070714035936/http://www.firewise.org/usa/files/ohio_plantlist.pdf","accessedOn":"2026-08-23T00:00:00.000Z"},{"source":"va-firescapes","verdict":"recommend","verdictRaw":"L flammability","claims":"Prized for its nut production.","edition":"2009","url":"http://web.archive.org/web/20090709143736/http://pubs.ext.vt.edu/430/430-300/430-300.pdf","accessedOn":"2026-08-23T00:00:00.000Z"},{"source":"fenz-low-flammability","verdict":"mixed","verdictRaw":"Moderate/high flammability","claims":"Moderate/high flammability classification.","plantPart":"shoot","edition":"2026","url":"https://www.checkitsalright.nz/reduce-your-risk/low-flammability-plants","accessedOn":"2026-08-23T00:00:00.000Z"},{"source":"gva-valencia","verdict":"recommend","verdictRaw":"recommended low-flammability species (shrubs, native/forest column)","claimOriginal":"especies recomendadas","edition":"2019","url":"https://www.leliana.es/sites/www.leliana.es/files/files/Jardineria%20de%20baja%20inflamabilidad.pdf","accessedOn":"2026-08-23T00:00:00.000Z"},{"source":"msu-e2948","verdict":"recommend","verdictRaw":"considered wildfire-resistant and are recommended for Michigan’s climate","claims":"Table 1 row: Corylus avellana (European filbert).","edition":"New, January 2007","url":"https://web.archive.org/web/20070714035839/http://www.firewise.org/usa/files/mi_wildfire_resistant.pdf","documentDate":"2007-01-01T00:00:00.000Z","accessedOn":"2026-08-25T00:00:00.000Z"},{"source":"girona-pirojardineria-2020","verdict":"recommend","verdictRaw":"MUY RECOMENDADA","claims":"Corylus avellana is rated “MUY RECOMENDADA” by the guide's qualitative IUF garden-suitability method. The method assumes species-specific care and integrates fire evidence with fuel structure, maintenance, origin, invasiveness, and expert fire-service experience.","sourcePlacement":{"value":"suitable inside or outside the 25-metre maximum-risk zone","scheme":"girona-2020-iuf-25m-suitability"},"edition":"2020 Spanish edition","url":"https://interior.gencat.cat/web/.content/home/030_arees_dactuacio/bombers/foc_forestal/publicacions_tecniques_i_normativa/guies_tecniques/prevencio_i_extincio/2020_Guia_de_pirojardineria_es.pdf","documentDate":"2020-01-01T00:00:00.000Z","accessedOn":"2026-08-25T00:00:00.000Z"},{"source":"flamits","verdict":"not-rated","verdictRaw":"calorific value (kcal/kg): 4424","score":{"value":4424,"scale":"FLAMITS — calorific value (kcal/kg)"},"claims":"FLAMITS record 5025; Combustibility measurement; plant part leaves; fuel all; predrying yes; device calorimeter; site Hough1969-3; sampling june. Primary study Hough1969: Hough, W. A. (1969). Caloric Value of Some Forest Fuels of the Southern United States. Res. Note SE-120. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station.","plantPart":"leaf","original":"Hough1969","edition":"Dryad version 9","url":"https://doi.org/10.5061/dryad.h18931zr3","documentDate":"2023-12-22T00:00:00.000Z","accessedOn":"2026-08-25T00:00:00.000Z"},{"source":"flamits","verdict":"not-rated","verdictRaw":"calorific value (kcal/kg): 4556","score":{"value":4556,"scale":"FLAMITS — calorific value (kcal/kg)"},"claims":"FLAMITS record 5026; Combustibility measurement; plant part twigs; fuel all; predrying yes; device calorimeter; site Hough1969-3; sampling june. Primary study Hough1969: Hough, W. A. (1969). Caloric Value of Some Forest Fuels of the Southern United States. Res. Note SE-120. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station.","plantPart":"shoot","original":"Hough1969","edition":"Dryad version 9","url":"https://doi.org/10.5061/dryad.h18931zr3","documentDate":"2023-12-22T00:00:00.000Z","accessedOn":"2026-08-25T00:00:00.000Z"},{"source":"mdfs-firewise-landscaping-plants","verdict":"recommend","verdictRaw":"relatively resistant to fire","claims":"Listed as Corylus avellana (European Filbert). The source says listed species exhibit stronger resistance to ignition by wildfires. Source comments: Prized for its nut production","plantPart":"whole-plant","sourcePlacement":{"value":"Deciduous Shrubs","scheme":"Maryland Firewise plant-form tables"},"edition":"2015 archived PDF","url":"https://web.archive.org/web/20250408035155/https://dnr.maryland.gov/forests/documents/fire/firewise_plants.pdf","documentDate":"2015-01-08T00:00:00.000Z","accessedOn":"2026-08-25T00:00:00.000Z"}],"flammabilityClass":"fire-resistant","ratingReason":"consensus","recommendation":"on-list","author":"grayson-graham","reviewStatus":"draft","lastVerified":"2026-08-23T00:00:00.000Z","reviewNotes":"Photo auto-selected (top-voted iNat); human review pending."},"localAssessmentInputs":{"stateDistribution":["DC","DE","MD","NJ","NY","OH","OR","PA","WA","WV"],"nativeStates":[],"rangeAssertions":[{"relation":"documented-occurrence","geography":{"grain":"state","stateCodes":["DC","DE","MD","NJ","NY","OH","OR","PA","WA","WV"]},"provenance":"legacy-field"}],"usdaZoneMin":"5a","usdaZoneMax":null,"hardinessAssertions":[{"minimum":"5","interpretation":"ambiguous-single-value","precision":"whole-zone","zoneMapping":"source-stated","applicability":"uncertain","applicabilityNotes":"The recovered selector prints one Cold Hardiness Zone value but does not define it as a minimum threshold or a one-zone range.","source":"fps-eastern-us","sourceRecordId":"corylus-avellana-contorted","sourceTaxon":"Corylus avellana 'Contorted'","taxonMatch":"exact","sourcePlacement":"Cold Hardiness Zone field in the recovered selector record","sourceVersion":"2016-wayback","asOf":"2026-08-26T00:00:00.000Z","provenance":"cited"},{"minimum":"4","maximum":"8","interpretation":"explicit-range","precision":"whole-zone","zoneMapping":"source-stated","applicability":"applicable","source":"msu-e2948","sourceRecordId":"shrub:Corylus avellana","sourceTaxon":"Corylus avellana","taxonMatch":"accepted-name","sourcePlacement":"Table 1, shrub row","sourceVersion":"New, January 2007","asOf":"2026-08-26T00:00:00.000Z","provenance":"cited"}],"hardinessSelection":{"status":"selected","assertion":{"minimum":"4","maximum":"8","interpretation":"explicit-range","precision":"whole-zone","zoneMapping":"source-stated","applicability":"applicable","source":"msu-e2948","sourceRecordId":"shrub:Corylus avellana","sourceTaxon":"Corylus avellana","taxonMatch":"accepted-name","sourcePlacement":"Table 1, shrub row","sourceVersion":"New, January 2007","asOf":"2026-08-26T00:00:00.000Z","provenance":"cited"},"assertions":[{"minimum":"5","interpretation":"ambiguous-single-value","precision":"whole-zone","zoneMapping":"source-stated","applicability":"uncertain","applicabilityNotes":"The recovered selector prints one Cold Hardiness Zone value but does not define it as a minimum threshold or a one-zone range.","source":"fps-eastern-us","sourceRecordId":"corylus-avellana-contorted","sourceTaxon":"Corylus avellana 'Contorted'","taxonMatch":"exact","sourcePlacement":"Cold Hardiness Zone field in the recovered selector record","sourceVersion":"2016-wayback","asOf":"2026-08-26T00:00:00.000Z","provenance":"cited"},{"minimum":"4","maximum":"8","interpretation":"explicit-range","precision":"whole-zone","zoneMapping":"source-stated","applicability":"applicable","source":"msu-e2948","sourceRecordId":"shrub:Corylus avellana","sourceTaxon":"Corylus avellana","taxonMatch":"accepted-name","sourcePlacement":"Table 1, shrub row","sourceVersion":"New, January 2007","asOf":"2026-08-26T00:00:00.000Z","provenance":"cited"}]},"invasiveIn":[],"statusAssertions":[{"status":"introduced-established","channel":"ecological","geography":{"grain":"aggregate-region","regions":["L48"]},"source":"us-riis-v2","sourceRecordId":"USRIIS-L48-Plantae7314","sourceVersion":"2.0 (November 2022)","asOf":"2022-10-23T00:00:00.000Z","sourceModified":"2017-11-21T00:00:00.000Z","sourceTaxon":{"name":"Corylus avellana","rank":"species","rawRank":"Species"},"sourceDesignation":{"code":"C3","label":"established (category C3)"},"associatedReferences":["USDA Natural Resources Conservation Service (NRCS) PLANTS Database (2021ang), https://plants.usda.gov/home/plantProfile?symbol=COAV80"],"taxonProjection":{"basis":"accepted-name","notes":"exact source identifier, rank, family, and scientific/accepted name"},"provenance":"cited"}],"fireEvidenceClass":"fire-resistant","recommendation":"on-list","fireSourceScopes":[{"source":"mdfs-firewise-landscaping-plants","sourceName":"Firewise Landscaping Plants (Maryland, New Jersey, and West Virginia editions)","sourceUrl":"https://web.archive.org/web/20250408035155/https://dnr.maryland.gov/forests/documents/fire/firewise_plants.pdf","geography":{"grain":"state","stateCodes":["MD"]},"completeness":"partial","reviewStatus":"reviewed","scope":"Maryland Forest Service says the list contains plants that can be grown in Maryland and identifies Maryland natives. FireApproved publishes 169 exact source owners from the 180 printed rows; an unrepresentable form and duplicate-owner rows are not broadened. The list calls itself non-comprehensive and does not establish suitability for every Maryland site.","sourceVersion":"Maryland-Firewise-Plants-2015-01-08","asOf":"2015-01-08T00:00:00.000Z"},{"source":"mdfs-firewise-landscaping-plants","sourceName":"Firewise Landscaping Plants (Maryland, New Jersey, and West Virginia editions)","sourceUrl":"https://www.nj.gov/dep/parksandforests/fire/docs/Firewise_Landscaping_Plants_for_NJ.pdf","geography":{"grain":"state","stateCodes":["NJ"]},"completeness":"partial","reviewStatus":"reviewed","scope":"New Jersey DEP publishes a state edition saying the listed plants can be grown in New Jersey and are relatively resistant to fire. Its same 180 printed taxon occurrences map to the 169 conservative owners already normalized for the template family. The list is non-comprehensive and does not establish suitability for every New Jersey site or override the Pinelands Commission's separate placement and fuel-break rules.","sourceVersion":"New-Jersey-Firewise-Landscaping-Plants-archive-2025-09-01"},{"source":"mdfs-firewise-landscaping-plants","sourceName":"Firewise Landscaping Plants (Maryland, New Jersey, and West Virginia editions)","sourceUrl":"https://wvforestry.com/pdf/Firewise%20Landscaping%20Plants%20for%20WV.pdf","geography":{"grain":"state","stateCodes":["WV"]},"completeness":"partial","reviewStatus":"reviewed","scope":"West Virginia Division of Forestry publishes a state edition saying the listed plants can be grown in West Virginia and are relatively resistant to fire. Its same 180 printed taxon occurrences map to the 169 conservative owners already normalized for the template family. The list is non-comprehensive and provides no comparative or site-specific rating.","sourceVersion":"West-Virginia-DOF-Firewise-Landscaping-Plants-live-2026-08-26","asOf":"2026-08-26T00:00:00.000Z"},{"source":"msu-e2948","sourceName":"Wildfire-resistant Landscape Plants for Michigan (Extension Bulletin E2948)","sourceUrl":"https://web.archive.org/web/20070714035839/http://www.firewise.org/usa/files/mi_wildfire_resistant.pdf","geography":{"grain":"state","stateCodes":["MI"]},"completeness":"partial","reviewStatus":"reviewed","scope":"Michigan State University Extension Bulletin E2948 is explicitly a list of wildfire-resistant landscape plants for Michigan and includes a Michigan-native field. FireApproved publishes 221 exact GBIF owners from 226 represented source rows and holds 15 complex or non-exact rows. This dated publication scope is not a current site-suitability determination.","sourceVersion":"MSU-Extension-E2948-2007","asOf":"2007-01-01T00:00:00.000Z"},{"source":"osu-b921","sourceName":"Firewise Landscaping (OSU Extension Bulletin 921)","sourceUrl":"http://web.archive.org/web/20070714035936/http://www.firewise.org/usa/files/ohio_plantlist.pdf","geography":{"grain":"state","stateCodes":["OH"]},"completeness":"partial","reviewStatus":"reviewed","scope":"Ohio State University Extension Bulletin 921 is an Ohio publication that describes Ohio fire seasons and landscape conditions and labels nativity to Ohio. FireApproved publishes 352 exact source-owning plant records from its eight rated tables. This historical publication scope does not assert current extension endorsement or that a listed plant suits every Ohio site.","sourceVersion":"OSU-Extension-Bulletin-921-2006","asOf":"2006-03-01T00:00:00.000Z"},{"source":"va-firescapes","sourceName":"Virginia Firescapes — Firewise Landscaping for Woodland Homes (430-300)","sourceUrl":"http://web.archive.org/web/20090709143736/http://pubs.ext.vt.edu/430/430-300/430-300.pdf","geography":{"grain":"state","stateCodes":["VA"]},"completeness":"partial","reviewStatus":"reviewed","scope":"Virginia Cooperative Extension's publication opens with Virginia wildfire conditions, identifies its Virginia Firewise Landscaping Task Force, and labels plants native to Virginia. FireApproved publishes 306 exact source owners. Publication scope does not establish parcel suitability or current endorsement of this archived 2009 list.","sourceVersion":"Virginia-VCE-430-300-2009","asOf":"2009-04-15T00:00:00.000Z"}],"firePerformanceConditions":[],"maintenanceAssertions":[],"maintenanceConditions":null,"regulatoryReviews":{},"seedReviews":{}},"legacyCompatibilityProjection":{"nativeStates":[],"invasiveIn":[],"usdaZoneMin":"4","usdaZoneMax":"8"},"localAssessmentContract":"Compare each dimension separately. State noxious-weed seed designations are material-scoped and never become non-seed plant restrictions, ecological-invasive findings, nursery restrictions, alternatives, product evidence, or fire votes. Introduced/established context is not an invasive warning. Minimum-only hardiness has no inferred maximum; canonical source-temperature conversion is validated and contradictory applicable rows project no primary zone. L48 context applies only to conterminous states and is never exact-state status. Fire-performance conditions are not maintenance advice. FEIS fire-ecology context does not vote in the plant classification. Absence of a status row is not regulatory clearance."}