Rodger makes some excellent points. There seem to be similar phenomena in epiphytic rhododendrons and bromeliads, where disturbance such as road building or logging creates light gaps that alter the behavior of pollinators and modify opportunities for the plants. Some vireyas are relatively uncommon in closed-canopy forest but roadsides in the same forest can create ideal secondary habitat for them to thrive and meet with congeners they would otherwise be more isolated from. The case is probably more dynamic with bromeliads like Guzmania species since their seeds are wind-dispersed. Regarding Narcissus, it's too bad there is not a formal taxonomic rank of "species complex" for a suite of closely allied taxa that may intergrade with one another-- or may be actively diverging from one common ancestor. Dylan