Finding connections like this, between concepts that I thought I understood but didn't realize were related to each other, is one of the things I like best about editing Wikipedia.
(The graphic matroid and geometric lattice articles are new. This matroid binge got kicked off when I started cleaning up the Fulkerson Prize article (congratulations to all the new winners!) and in doing so was reminded about Rota's conjecture. Other new matroidality: matroid minor, partition matroid, regular matroid, uniform matroid. )