funkychips, i'm not sure of this, but from the numerous gracilis I see growing wild along the N-S highway, most grow on rocky slopes which are exposed to the elements. I think in this case, a waxy costing on the leaves is more important as it prevents excessive drying out through transpiration. On the other hand, most neps with hairy leaves tend to grow where precipitation and humidity are high (primary and cloud forests), so they don't dry out as much. Not sure about albo though.. Maybe its just more tolerant of drying out than others..
