Chilean wood sorrel or silver shamrock concludes this week’s series on flowering plants of South America. This is a plant that can grow in most temperate regions of the world, either outdoors or as a houseplant.
I apologize for not succeeding in getting a photograph of the whole plant. This species has the behaviour of only opening its flowers with direct sunshine. I noticed a plant in spectacular bloom in the late morning yesterday while touring a friend around UBC Botanical Garden, but a return to it in the late afternoon was unproductive photographically; its flowers had closed for the day thanks to the shade (see photograph in comment below). An additional attempt this morning was unfruitful, as I suppose some of the flowers were now in the process of senescence. Close-up photographic opportunities of flowers of not-quite-as-photogenic plants were available, though.
The silver shamrock common name is in reference to the greyish leaves. The link includes photos of the plant, as well as a new word for me, obdiplostemonous, a property of species of Oxalis meaning “there are twice as many stamens as petals, and they are arranged in two rings with the outer ones opposite the petals.”
Oxalis adenophylla is native to alpine regions of Chile and Argentina, where it grows on talus slopes (photos of the species in habitat). There are reports of plants in cultivation tolerating temperatures of -30 Celsius (-22F) for two weeks.