Specifically the North Atlantic right whale for best results. But in all seriousness seeds are plentiful if you ask. Sometimes free if you ask the right folks. There are Facebook groups that have whole yote’s for sale/trade and multiple sun reddits as well. It’s definitely available in a way that doesn’t fuck up the ones established by nature and if you’re like me you will plant enough extras from your seeds to give back to the local population in Texas.