{"id":"claytosmunda-claytoniana","license":"CC-BY-4.0","data":{"scientificName":"Osmunda claytoniana","commonNames":["Interrupted fern"],"taxonRank":"species","acceptedName":"Claytosmunda claytoniana","family":"Osmundaceae","ids":{"usdaSymbol":"OSCL2","gbifKey":9684539},"usdaZoneMin":"3a","zoneSource":"usda-plants","states":["AL","AR","CT","DC","DE","GA","IA","IL","IN","KY","MA","MD","ME","MI","MN","MO","MS","NC","NH","NJ","NY","OH","PA","RI","SC","TN","VA","VT","WI","WV"],"hardinessAssertions":[{"minimum":"3a","interpretation":"minimum-threshold","precision":"half-zone","zoneMapping":"derived-containing-band","sourceMeasurement":{"kind":"minimum-temperature","value":-38,"unit":"degrees-fahrenheit"},"applicability":"applicable","source":"usda-plants-characteristics","sourceRecordId":"OSCL2","sourceTaxon":"Osmunda claytoniana","taxonMatch":"source-identifier","sourcePlacement":"PlantCharacteristics record 14166, Temperature, Minimum (°F)","sourceVersion":"PLANTS Help Document 2022; characteristics cache retrieved 2026-08-23","asOf":"2026-08-26T00:00:00.000Z"}],"plantForm":"perennial","matureHeightFt":4,"waterNeed":"high","photo":{"file":"/images/plants/claytosmunda-claytoniana.jpg","sourceUrl":"https://www.inaturalist.org/photos/198402683","license":"cc-by","attribution":"(c) Marilyne Busque-Dubois, some rights reserved (CC BY), uploaded by Marilyne Busque-Dubois","fetchedOn":"2026-08-24T00:00:00.000Z"},"evidence":[{"source":"dibble-2007-northeastern-invasives","verdict":"recommend","verdictRaw":"low effective heat of combustion (author-named group)","score":{"value":11.53,"scale":"AEHOC-MJ-kg"},"claims":"Conditioned foliage and twigs were tested at 25 kW/m2 in a cone calorimeter.","plantPart":"shoot","condition":"cured","edition":"2007","url":"https://research.fs.usda.gov/download/treesearch/31137.pdf","documentDate":"2007-08-20T00:00:00.000Z","accessedOn":"2026-08-24T00:00:00.000Z"},{"source":"flamits","verdict":"not-rated","verdictRaw":"calorific value (kcal/kg): 2985.57","score":{"value":2985.57,"scale":"FLAMITS — calorific value (kcal/kg)"},"claims":"FLAMITS record 2878; Combustibility measurement; plant part leaves; fuel live; predrying yes; device calorimeter; site Dibble2007-1; sampling ND. Primary study Dibble2007: Dibble, A. C., White, R. H., & Lebow, P. K. (2007). Combustion characteristics of north-eastern USA vegetation tested in the cone calorimeter: invasive versus non-invasive plants. International journal of wildland fire, 16, 426-443.","plantPart":"leaf","original":"Dibble2007","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"}],"flammabilityClass":"fire-resistant","ratingReason":"limited-evidence","recommendation":"on-list","author":"grayson-graham","reviewStatus":"draft","lastVerified":"2026-08-24T00:00:00.000Z","reviewNotes":"Photo selected from license-verified candidates and human-reviewed 2026-08-24 (joint session)."},"localAssessmentInputs":{"stateDistribution":["AL","AR","CT","DC","DE","GA","IA","IL","IN","KY","MA","MD","ME","MI","MN","MO","MS","NC","NH","NJ","NY","OH","PA","RI","SC","TN","VA","VT","WI","WV"],"nativeStates":[],"rangeAssertions":[{"relation":"documented-occurrence","geography":{"grain":"state","stateCodes":["AL","AR","CT","DC","DE","GA","IA","IL","IN","KY","MA","MD","ME","MI","MN","MO","MS","NC","NH","NJ","NY","OH","PA","RI","SC","TN","VA","VT","WI","WV"]},"provenance":"legacy-field"}],"usdaZoneMin":"3a","usdaZoneMax":null,"hardinessAssertions":[{"minimum":"3a","interpretation":"minimum-threshold","precision":"half-zone","zoneMapping":"derived-containing-band","sourceMeasurement":{"kind":"minimum-temperature","value":-38,"unit":"degrees-fahrenheit"},"applicability":"applicable","source":"usda-plants-characteristics","sourceRecordId":"OSCL2","sourceTaxon":"Osmunda claytoniana","taxonMatch":"source-identifier","sourcePlacement":"PlantCharacteristics record 14166, Temperature, Minimum (°F)","sourceVersion":"PLANTS Help Document 2022; characteristics cache retrieved 2026-08-23","asOf":"2026-08-26T00:00:00.000Z","provenance":"cited"}],"hardinessSelection":{"status":"selected","assertion":{"minimum":"3a","interpretation":"minimum-threshold","precision":"half-zone","zoneMapping":"derived-containing-band","sourceMeasurement":{"kind":"minimum-temperature","value":-38,"unit":"degrees-fahrenheit"},"applicability":"applicable","source":"usda-plants-characteristics","sourceRecordId":"OSCL2","sourceTaxon":"Osmunda claytoniana","taxonMatch":"source-identifier","sourcePlacement":"PlantCharacteristics record 14166, Temperature, Minimum (°F)","sourceVersion":"PLANTS Help Document 2022; characteristics cache retrieved 2026-08-23","asOf":"2026-08-26T00:00:00.000Z","provenance":"cited"},"assertions":[{"minimum":"3a","interpretation":"minimum-threshold","precision":"half-zone","zoneMapping":"derived-containing-band","sourceMeasurement":{"kind":"minimum-temperature","value":-38,"unit":"degrees-fahrenheit"},"applicability":"applicable","source":"usda-plants-characteristics","sourceRecordId":"OSCL2","sourceTaxon":"Osmunda claytoniana","taxonMatch":"source-identifier","sourcePlacement":"PlantCharacteristics record 14166, Temperature, Minimum (°F)","sourceVersion":"PLANTS Help Document 2022; characteristics cache retrieved 2026-08-23","asOf":"2026-08-26T00:00:00.000Z","provenance":"cited"}]},"invasiveIn":[],"statusAssertions":[],"fireEvidenceClass":"fire-resistant","recommendation":"on-list","fireSourceScopes":[{"source":"dibble-2007-northeastern-invasives","sourceName":"Combustion characteristics of north-eastern USA vegetation tested in the cone calorimeter","sourceUrl":"https://research.fs.usda.gov/treesearch/31137","geography":{"grain":"aggregate-region","stateCodes":["ME","MD","MA","NY","VA"],"regions":["Northeastern and mid-Atlantic study sites"]},"completeness":"partial","reviewStatus":"reviewed","scope":"The authors collected foliage and twigs across study sites in Maine, Maryland, Massachusetts, New York, and Virginia, then conditioned and tested the samples in a cone calorimeter. FireApproved publishes 37 exact source owners only as multi-state laboratory context. The source does not establish that every taxon was sampled in every named state, whole-plant behavior, landscape suitability, or state planting guidance.","sourceVersion":"USDA-Treesearch-31137-2007","asOf":"2007-08-20T00:00:00.000Z"}],"firePerformanceConditions":[{"condition":"cured","evidence":[{"source":"dibble-2007-northeastern-invasives","verdict":"recommend","url":"https://research.fs.usda.gov/download/treesearch/31137.pdf","claims":"Conditioned foliage and twigs were tested at 25 kW/m2 in a cone calorimeter.","evidenceIndex":0}]}],"maintenanceAssertions":[],"maintenanceConditions":null,"regulatoryReviews":{},"seedReviews":{}},"legacyCompatibilityProjection":{"nativeStates":[],"invasiveIn":[],"usdaZoneMin":"3a"},"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."}