>>43825927NTA. Biology is just a really complicated tech desu, I can envision some kind of bio-thruster. Synthesize some energy-dense sap, pump it into a chamber with a heart thing, ignite the combustible with the spark of some kind of electrical organ like in an electric eel, grow an expansion bell with mineralized materials like in a snail's shell. If you prefer to not have the saplings rocketing around that's totally fine though.
I just gave this some thought because I plan on having something like that. 