River Bubbleweed

The river bubbleweed split from purple sea bubbleweed. It is exactly the same in every way, except that it can grow in freshwater. It grows up and down the Bone River to the Bone Swamp. Like its ancestor, it still has hydrogen-filled seed bubbles; these bubbles also keep the leaves upright and buoyant in the water. This works much like Earth's  kelp, except that when its bubbles fall off they actually float up and out of the water into the air before landing back into the water. They reproduce asexually with these bubble seed/spores.