The Azalea Tree is one of the many new features in the Minecraft Caves and Cliffs update, did we mention Part 1 is available right now?

Where To Find A Lush Cave In Minecraft Lush Caves generate underground at any height, they are uncommon in rarity but can be located by finding an Azalea Tree above ground.

Minecraft's Caves and Cliffs update is filled with new blocks, new mobs to tame and breed, and even new biomes like the underground Lush Caves biome.