Milkweed Host for Monarch Butterfly

My name is John Wiggers and I am looking for a source of milkweed seeds or plants, for me to plant on my property in Port Perry as a means of attracting and supporting Monarch Butterflies.
In searching the web I came across your website. I am already familiar with your company because of the Toronto Star article a while back. I see that you sell milkweed seeds from your online catalogue....are these the same species that attract Monarchs?

Yes, our milkweed, known botanically as Asclepias syriaca, is one of the favoured host plants for the monarch butterfly. Other members of the Asclepias genus are also important hosts for the monarch, including bloodflower (Asclepias curassivica) and pleurisy root (Asclepias tuberosa). All three are available from Richters:
Bloodflower: www.richters.com/Web_store/web_store.cgi?product=X1440
Milkweed: www.richters.com/Web_store/web_store.cgi?product=X3995
Pleurisy root: www.richters.com/Web_store/web_store.cgi?product=X4510
For a short list of other butterfly attracting herbs see: www.richters.com/questions-and-answers/04-19980331-68