Matt,
You just made me feel kind of stupid, I put so much thought into legally collecting them I never gave much thought into legal restrictions of shipping to other states. I had so many phone meetings with TPWD without even giving that any thought. I will need to look into that. The Black Mangrove exists almost worldwide in tropical seas so I would imagine if it can live somewhere it would already be there. I can't imagine it is a real threat but I suppose that doesn't mean they are necessarily legal. Does California restrict the Red Mangrove?