The phytogeography of Oxalis oregana in British Columbia

The occurrence of Oxalis oregana Nutt. in British Columbia is documented for five localities on the west coast of Vancouver Island and one locality in the Queen Charlotte Islands. The Oxalis populations grow in alluvial Tsuga heterophylla – Picea sitchensis – Thuja plicata – Polystichum munitum forest communities. Rhizomatous reproduction was recorded in all populations and flowering in two of the Vancouver Island populations. Three of the populations may be less than 3000 years old because they would have been inundated by higher sea levels during the middle Holocene. Possible introduction of plants by native people from the Olympic Peninsula, WA, is discussed.