Jared-
I recently came across a copy of a report written in 1909 discussing the plants used to produce rubber in Mexico. Now, I wasn't even aware that Mexico produced rubber or had any native plants that could be used to produce it. However, there are, apparently, three different plants that can be tapped to yield a sap that may be processed into usuable rubber. To be clear, I'm using rubber in the broader sense here including things like gutta-percha as that seems to be how it's used in the report. Indeed it compares the rubber from one of the plants to gutta-percha and comes to the conclusion that it they are very similar. The most relevant part of the article was the one discussion the tree Castilla elastica which grows in Mexico but also in the West Indies. If it can be cultivated in the islands of the West Indies it should be suitable for cultivation in the Yucatan too. It strikes me that this tree could be a potential crop for the Yucatan. If it's profitable enough it could be a significant incentive to maintain control of the Yucatan and complete the subjugation of the Maya for labor. Or, more horrifically, exterminate them and bring in slave labor from the rest of the United States to work the rubber plantations.
Just my thoughts.