It's also impossible to get the real Greek oregano from seed. It must be started from cuttings. It's a very hardy perennial, and easy to grow in a pot, as long as you keep it watered.
This year we planted some Mexican Oregano that I bought on eBay from a woman who said it washer Abuela's secret ingredient. It was broad-leafed like 1-2 inches and thick and fuzzy like a cactus. Not sure what it really was, it did smell oregano-y. But it died during transplant to the garden.
We also planted (successfully!) "Hot and Spicy Oregano." I thought, 'Right, how hot could it be?" It's HOT! I dropped a sprig in a tomato sauce today and you'd think I had put in chili flakes. Excellent and highly recommended!
I guess I'm not answering the question at all, but the title was "Oregano Types" and I figured someone might appreciate the info!
I asked because I can buy "bulk" spices at my local grocer. they have "Greek" oregano, but not "Italian". They have a very good "Italian Blend" of spices that I buy often, but I wanted to see what just strait Oregano would taste like on a Chicken...