Cave-dwelling plants? What are they, members of the Bataceae? OK, that's just a name joke. The family is real, an Australian endemic and halophyte, but they don't live in caves like bats. And there is a bat flower too, but still not right, although this genus (Tacca) grows in pretty deep shade. No, these cave dwelling plants, which grow in very, very dim light, are members of the nettle family. The level of illumination can be as low as 0.04% of full sunlight. That's about like growing in your closet. Hey, maybe we have some new candidates for houseplants here, but they probably need to be fertilized by bat guano.