United States / Grow / interrupted fern

interrupted fern (Osmunda claytoniana)
Photo: (c) Marilyne Busque-Dubois, some rights reserved (CC BY), uploaded by Marilyne Busque-Dubois (CC BY), via iNaturalist. Species-typical, not necessarily this cultivar.

interrupted fern

Osmunda claytoniana (accepted: Claytosmunda claytoniana) · Osmundaceae

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Enter your ZIP to see whether this is legal to plant in your state, and whether it survives your winter.

Osmunda claytoniana opens with Combustion characteristics of north-eastern USA vegetation tested in the cone calorimeter. For Osmunda claytoniana, limited evidence remains the separate depth label. That is not one slogan on Osmunda claytoniana. Interrupted fern is the vernacular name attached to Osmunda claytoniana.

Osmunda claytoniana still has cured test condition after that lead pair. Osmunda claytoniana does not pick only one of those facts on Osmunda claytoniana.

Open the evidence table for Osmunda claytoniana; test conditions cited for Osmunda claytoniana. Those jumps stay with Osmunda claytoniana rather than copying rows.

Form
perennial
Mature height
~4 ft
Water need
high
Rated in
Global; north-eastern and mid-Atlantic United States
On this lot

1. Fire evidence and conditions

Fire evidence
Fire-resistant — location does not change the cited classification.
Fire-performance conditions
1 condition stated in cited fire-evidence rows.
Evidence regions
Global; north-eastern and mid-Atlantic United States
Typed publication scope: 1 scope across 1 cited fire source
  • Combustion characteristics of north-eastern USA vegetation tested in the cone calorimeter · Official scoped edition
    • Northeastern and mid-Atlantic study sites (ME, MD, MA, NY, VA footprint); partial normalized coverage · 2007-08-20

      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.

2. Why this plant is relevant here

State distribution
Documented in 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.
USDA hardiness
Documented minimum 3a; no upper limit is documented.

3. Legal, ecological, and broader status

How to read this page

The status above is computed from the cited rows below: independent recommendations can support a fire-resistant result, an avoid row can produce keep-away, and disagreement stays visible as conflict. Placement notes preserve each source’s own scheme rather than translating unlike rules into one scale. This is evidence about a plant, not permission to plant it in every part of the defensible space; Zone 0 remains noncombustible.

Plant hardiness evidence

These values describe the plant source. Your ZIP zone comes from the separate 2023 USDA Plant Hardiness Zone Map. Whole-zone values stay whole-zone, and a single unresolved value is not treated as a tolerance range. Different source boundaries stay separate: overlapping statements are compared independently, while only ranges with no shared zone are called a conflict.

Conditions in the fire evidence

These describe tested or rated plant material. They are not horticultural maintenance instructions.

The evidence

Grouped by what each source concluded. Primary evidence rated the plant itself (a lab, field program, or original curation); corroboration compiled or republished another source's rating and resolves to its root lineage.

Recommends (1)

Listed without a rating (1)
Corroboration (1 rows from 1 source)
  • FLAMITS: FLAMmability plant traiTS database — Dryad / Global Ecology and Biogeography · Dryad version 9 · original source Corroboration Trait database lineage: meta-aggregator

    “calorific value (kcal/kg): 2985.57”

    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.

Last verified 2026-08-24. JSON (CC BY 4.0)

Profiles: USDA PLANTS · GBIF · iNaturalist · Wikidata ·

Osmunda claytoniana (Interrupted fern). FireApproved. https://fireapproved.com/plants/claytosmunda-claytoniana/. Last verified 2026-08-24.