{
  "format_version": "1.21.40",
  "minecraft:single_block_feature": {
    "description": {
      "identifier": "minecraft:jungle_fern_feature"
    },
    "places_block": {
      "name": "minecraft:fern"
    },
    "enforce_survivability_rules": true,
    "enforce_placement_rules": false,
    "may_replace": [
      "minecraft:air"
    ],
    "may_not_attach_to": {
      "bottom": "minecraft:podzol"
    }
  }
}