Piperia transversa Suksd., syn. Platanthera transversa (Suksd.) R.M.Bateman, is a species of rein orchid (known specifically as the royal rein orchid) native to North America from California north to British Columbia. It grows in a variety of habitats from chaparral to forest, often in areas that dry out in summer at elevations below 2600 m. The species can be identified from other Piperia species by its mostly white flowers, spurs mostly perpendicular to the scape, and mild scent at night (not always detectable). The basal leaves are usually withered by the time it blooms, late May to August.
The first three photos by Travis Owen show plants growing under Douglas-fir, oak, and madrone trees with Mahonia, Lonicera, and Toxicodendron. Dodecatheon hendersonii and Erythronium hendersonii also grow here, giving clues to its culture. The last two photos were taken by Mary Sue Ittner.