{
  "feature": "minecraft:azalea_tree",
  "placement": [
    {
      "type": "minecraft:block_predicate_filter",
      "predicate": {
        "type": "minecraft:matching_blocks",
        "blocks": [
          "minecraft:moss_block",
          "minecraft:sand",
          "grass_block"
        ]
      }
    }
  ]
}