Q.Indoor Yucca Plant
Hi, I have a small indoor yucca plant, I was wondering what the black is that has been placed on top. What is it and what is it’s purpose? Thanks

Certified GKH Gardening Expert
This is, simply, a seal for when the plant was pruned. In a nursery setting, where there are many trees in one spot, it is useful to keep diseases to a minimum.
This treatment isn't, usually, necessary in the home setting.
This will not harm your plant, nor will you need to do anything with it.
Here is an article that will help you to care for them, indoors: https://www.gardeningknowhow.com/ornamental/foliage/yucca/growing-yucca-indoors.htm