Sea Oats are a non-solid, two-block tall plant blocks capable of generating sand.
Sea Oats can be obtained using Shears or Silk Touch enchanted tools. If mined without, nothing is dropped.
Natural generation Sea Oats generate in Beach biomes touching other blocks, so they will regularly be found touching the edges of sand.
Post-generation Using Bonemeal on Sea Oats makes it drop an item copy.
Sea Oats can be planted on any sand block, and will spawn random particles of the sand block. These particles are increased if it is capable of Dune Growth.
If the bottom half of Sea Oats are touching a solid side of a block, it will have the chance to randomly replace it's bottom half with the same type of sand block it is planted on. The works with vanilla normal and Red Sand, along with any modded sand extending vanilla's sand block.
When the bottom half is replaced by sand, the top half has a unique short texture. Using bonemeal will extend it into a new two-block Sea Oats, while mining the sand below will replace the bottom half again, allowing for continued generation.