MCU headcanon:
Flora Colossus (Groot’s species) don’t ever stop growing due to their regenerative capabilities. The oldest members were said grow to thousands of meters tall. It’s why Yggdrasil is referred to as the world tree, as in some Asguardian legends, it’s said it was once a flora colossus that grew so old and so impossibly large that it transcended its physical being and became the nebula that connects the realms together. It’s partly why Groot’s language is taught as an elective, as it’s believed to be a sacred language.
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