I'm glad to learn this new information about Oxalis, even if I can't elicit an actual article! Regarding winter-hardiness, it is a common misconception that high-alpine species should be hardy in cold climates in lowland gardens. If a plant, especially a geophyte, spends the winter under a deep blanket of snow, it won't necessarily survive repeated freeze and thaw cycles without snow cover during a temperate climate winter -- especially if it's wet when it freezes. That's why many alpines are grown under cover even though "perfectly hardy." It's not the cold, it's the humidity.... It can also be difficult to maintain plants that have evolved to undergo a very long winter dormancy, unless you're growing them in a region with a similarly long winter. Wonderful alpines are grown at or near sea level in countries around the North Atlantic, for instance, and if you go up by the Arctic Circle, you can view such plants in comfort without ever getting out of breath, because they're just above the beach. I saw the same species at 1000 meters elevation in Alaska and 4000 meters in Colorado. This is Rock Gardening 101 -- I apologize to those who are both bulb and alpine enthusiasts and know it already. Christaan wrote, All the "spreading" and "invasiveness" of (South african) bulbous Oxalis is >thus more due vegetative reproduction, and if Oxalis are kept in a pot, this >should keep the species where you want it to be. I say should, becouse >Oxalis roots can grow very deep, and if the pot is placed directly on (or >in) a suitable growing medium, the roots can go through the holes in the pot >and into the soil, and voila ! an escapee ! - most probably this is the >source of Jane's plants in the plunge sand. Yes, it is; more than that, they will come UP through the drain holes into other pots. In the case of little O. obtusa this is probably harmless and can be charming: a pot of blue Juno iris surrounded by pink oxalis flowers is very pretty. However, I have to comb all the Oxalis tubers out of the other plants' roots when I repot them if this happens. I'll try not to introduce the Oxalis to the bulb house when I move, but it may be a lost cause. In addition to the little Oxalis species of temperate South America, there is at least one really big one, O. gigantea, which is a shrub and I imagine there are similar manifestations in southern Africa. The South American one is more of a curiosity than a beauty, but that could be said of a lot of "succulents." Jane McGary Northwestern Oregon, USA