The two beings have a similar geometric richness and complexity and, I suppose, the same principles of biochemical structural engineering are at work. Are those ribs or veins?
Probably both. The extra thickness of tissue gives strength and support, and perhaps the ribs also contain long bundles of tube (I’m speculating here, I’m no botanist) for fluid and nutrient transport.
In youth they are smoother in aspect:
The crenelations and valleys come with aging, and I don’t even know how old these plants are. Oh yes, 2 months or so, but relative to their life cycle?