It looks like an old mineral crystal. "Strange plant-like" sounds very amateurish and does not reflect facts.
Of course if someone thinks that doesn't look like a plant but crystal or an animal, they are fre to describe it as "crystal-like" or "animal-like".
Its alright bo be impressed with its looks I guess, noone is going to make a salad of it, so it is not dangerous to think that it looks like a plant.
1: https://study.com/academy/lesson/sea-sponge-lesson-for-kids....
Not a meteorologist, but from all I understand it means lens-shaped, and to me that immediately gives a strong clue as to how they form since lenses have focal points and can, to some degree, have shapes expressed as formulae about some origin. Which to me is suggestive of the relation to the mountains around which they form.