Is there a list of xeric and mesic varieties?

"Xeric" and "mesic" are more of a spectrum than hard and fast classifications- some xeric plants are more xeric than others. I believe the rule-of-thumb is that the amount you water should be inversely proportional to how visible the plant's trichomes are (how fuzzy it is). The trichomes absorb moisture and protect the plant from harsh sunlight, so less water goes further. Lots of large trichomes means they've adapted for bright, dry conditions and are xeric. Fewer, nearly invisible trichomes means they've adapted for shady, humid conditions and are mesic. The size of the plant also affects how much water it needs, as thicker, larger leaves can store more water. For this reason, a small pruinosa might need more frequent watering than a large caput medusae even if its trichomes are larger.

/r/airplants Thread