Philadelphus lewisii (Lewis' mock-orange)—also known as Gordon's mockorange, Indian arrowwood, wild mockorange (though this can apply to any species in the genus) and syringa—a name that usually refers to the unrelated lilacs.—is a deciduous shrub native to western North America, from northwestern California in the Sierra Nevada, north to southern British Columbia, and east to Idaho and Montana. It is widespread but not very common, usually appearing as an individual plant amongst other species. It was first collected by scientist and explorer Meriwether Lewis in 1806 during the Lewis and Clark expedition and the Philadelphus lewisii is named after him.