Philadelphus lewisii by A. BarraPhoto by A. Barra

Fast Facts

  • Adopted the Idaho state flower in 1931
  • Botanical name: Philadelphus lewisii
  • Common name: Lewis Mock Orange
  • Syringa trivia: The syringa is a member of the hydrangea family.
  • Idaho Flower Delivery

Like many other states, Idaho representatives took up the matter of choosing a state flower shortly after their state entered the union. They chose the syringa, an attractive wildflower that turns Idaho hillsides a snowy white in late springtime with its great clusters of flowers.

Though the state did not officially make the syringa the Idaho state flower until 1931, in reality the flower became the Gem State’s floral emblem much earlier: in the 1890s, syringa was depicted on the Great Seal of the State of Idaho, growing at the feet of a female goddess. Several years later it represented Idaho in a floral display at the 1893 World’s Exposition in Chicago.

Philadelphus lewisii by Joaquim Alves GasparPhoto by Joaquim Alves Gaspar

The Idaho state flower is a flowering shrub that grows between four and eight feet tall. Its flowers grow in clusters at the end of its branches. Each has four to five waxy petals and numerous yellow stamens. While its flowers are remarkable, Idaho’s state flower is also known for its strong, sweet fragrance. Similar to that of the orange blossom, the syringa’s scent earned the wildflower the nickname of “mock orange.”

The syringa’s range is a wide one. It grows from British Columbia to the northern California, western Montana and east to Idaho. Within the state, the Idaho state flower grows well in central and northern Idaho. Residents of the state’s most populous cities, Boise, Nampa and Idaho Falls, can travel to the state’s many wilderness areas to see the Idaho state flower. In the Boise National Forest, syringa grows well in moist to semi-moist soil found along streams, dry ravines, rocky areas and canyons. By one account, syringa is at its peak along Idaho’s rivers at the same time that Chinook salmon are migrating upstream.

The Idaho state flower’s botanical name speaks to its historical roots: Lewisii comes from Captain Meriwether Lewis of the Lewis and Clark expeditions. Lewis, a scientist as well as explorer, collected samples of syringa during the pair’s famous travels across northern America. He was not the first to “discover” the plant, however. Native Americans used its straight and strong branches to make arrows, pipes and combs.


U.S. Forest Service

A Field Guide to Rocky Mountain Wildflowers,M1