"convergent": You probably meant "convergently".
I suggest you remove those tiny white specks between the bubble seeds of some branches, although they are so small this is optional.
"due to its ancestor's branches" Can you clarify what you mean by this? I suggest: "its ancestor's branches occasionally were knocked down, and as it split off from its ancestor, it consequently developed a countermeasure against the branches being knocked down."
"floating It". There's a missing period.
"hydrogen filled" I recommend: "hydrogen-filled".
Things in the template at the top are generally capitalized.
Unless its bubble-leaves are different from is ancestor's, I recommend clarifying the shape of the bubbles. Right now, they look kind of like Hawaiian halfflowers or stylized baobabs.
Are there conditions where its bubble-leaves don't float? It would appear such, judging by one branch's tip facing downward.
While functional at its size, a little more detail could improve the description, such as the function of the onion-flavored bubble seeds