A Small Dripleaf can be a rare item that you can find in Minecraft. For Minecraft’s update 1.17, the only way to obtain this item is by speaking with a Wandering Trader. They’re willing to offer you a single emerald for the item, and you’ll receive two of them that you can set down on specific blocks, namely clay and moss. You can also place them on dirt, farmland, grass, and podzol blocks, but these need to be underwater, unlike clay and moss.
Although the Small Dripleaf is considered a plant and looks like a vine, it does not grow when you place it on top of a block. Even when you place it on the blocks that have it underwater. A Small Dripleaf does not have a natural growth cycle, and no matter how long you wait, it will never transform into its next stage, a Big Dripleaf. Instead, the only way to have it grow is to feed it bone meal. Once it receives bone meal, it instantly becomes a Big Dripleaf, and you can use it to reach higher locations that you normally would have trouble reaching.
There are also no seeds or starting forms for a Small Dripleaf. You can only find them from Wandering Traders or by obtaining them from Lush Caves, which have not launched to Minecraft yet. They will naturally grow in these biomes.