The Aroid Cultivar Registry of the International Aroid Society, which is the registering body for aroids, details that this plant was originally found in the collection of Roberto Burle Marx and registered in 1981. It is unknown where it was collected (Burle Marx was bad about that). Some sources say (without proof) that it is a hybrid if Monstera dilacerata x insulare. It most closely resembles Monstera deliciosa var sierrana, which has since been 'demoted' as a var and reclassified as a simple synonym for M. deliciosa. These were wildly expensive when they first hit the US market. Now that they are in tissue culture they are slowly getting more reasonable in price. I'm sure they will show up for $19.95 via Costa Farms at the box stores in due time.