Howdy All, I think that Oxalis tuberosa is also known as "New Zealand Yam" from memory, just in case that helps any in searching? I have been meaning to buy some for my oxalis collection for a while now from a nursery an hour or so away from here which is the only place I have seen it for sale except ocassionally by mail order. I never realised it was oca/ocha. Cheers. Paul Tyerman Canberra, Australia. USDA equivalent - Zone 8/9 Growing.... Galanthus, Erythroniums, Fritillarias, Cyclamen, Crocus, Cyrtanthus, Oxalis, Liliums, Hellebores, Aroids, Irises plus just about anything else that doesn't move!!!!!