Lewis mockorange, known almost universally throughout its range as syringa, 

 has been legally adopted as the State flower of Idaho. The name syringa is 

 not satisfactory in this case, since Syringa is the generic name of the cultivated 

 lilacs, and also because the name signifies a pipe or trumpet, an application 

 totally inappropriate for mockorange flowers. Indian arrowwood is another 

 name sometimes given to this plant because the Indians used its slender shoots 

 for arrow shafts. 1 The specific name of this attractive shrub is an honorary 

 tribute to Captain Meriwether Lewis of the Lewis and Clark expedition, who 

 discovered and first collected the plant on July 4, 1806, along the Clark Fork 

 River, near Missoula, Mont. 2 



Lewis mockorange, the best known and most outstanding western species of 

 mockorange, is distributed from British Columbia, and the Cascade Mountains 

 of Washington and Oregon, to California and eastward to Montana and northern 

 Utah. The California plants are regarded by some authorities as a variety, 

 P. lewisii caJifomicus. Lewis mockorange grows on a variety of sites, but 

 occurs principally on or near canyon bottoms or in other moist, moderately 

 shaded, or open situations. It grows on soils varying from deep, rich, alluvial 

 humic loams to dry, rocky or gravelly loams on open hillsides, usually in typical 

 association with alder, chokecherry, dwarf maple, and willow, or on the drier 

 sites, with bitterbrush, dogbane, mullein, ponderosa pine, serviceberry, and snow- 

 brush. This shrub of the foothills and low mountains extends from near sea 

 level to about 8,000 feet and thrives on all slopes, but favors northerly or 

 easterly exposures. It usually occurs in small, scattered clumps, being common 

 only in restricted localized areas, but is not abundant enough over the range as 

 a whole to form a very important part of the plant cover. 



As a forage plant Lewis mockorange is of minor importance and usually is 

 not grazed by domestic livestock on any extensive scale. However, there are 

 exceptions, as in eastern Oregon where it is eaten to a limited extent by cattle, 

 and in central Washington where its palatability is rated as fair for both 

 cattle and sheep. As a game forage Lewis mockorange merits a higher rating. 

 In Montana, deer browse it readily, especially on the winter ranges ; in Wash- 

 ington both deer and elk relish this shrub. It is quite likely that game ani- 

 mals utilize this plant elsewhere in its range. 



Lewis mockorange, a most attractive shrub when in full bloom, has attained 

 great popularity and is widely cultivated for ornamental purposes. It grows 

 from 3 to 12 feet high and has ascending or spreading branches. The twigs 

 branch oppositely and have red or chestnut-brown bark which during the 

 second season develops conspicuous cross cracks. The showy, white flowers 

 are fragrant and are borne singly on short stems or in loose terminal clusters 

 (cymes). 



Lewis mockorange is sometimes confused with Gordon mockorange (Phila- 

 delphus ffordoniamts ) , a popular and showy shrub of the Northwest which 

 grows principally in the coast region from British Columbia to northern 

 California. The leaves of Lewis mockorange have entire or but slightly 

 toothed margins and are hairy around the edges, on the veins, and in the axils 

 of the veins on the lower surface ; the blades are three-to five-veined with the 

 inner pair of veins meeting the midrib at some distance from the base of the 

 blade. Gordon mockorange has leaves which are usually toothed, often 

 coarsely, and are fine-hairy over the under surfaces and five-veined, the veins 

 originating at the base of the blade. In Gordon mockorange the styles are 

 united for two-thirds of their length, while those of Lewis mockorange are 

 united for about half their length. 



1 Jepson, \V. L. A MANUAL OF THE FLOWERING PLANTS OF CALIFORNIA. 1,238 pp., illus. 

 Berkeley, Calif. [1925.] 



a Piper, C. V. FLORA OF THE STATE OF WASHINGTON. U. S. Natl. Mus., Contrib. U. S. 

 Natl. Herbarium 11, 637 pp., illus. 1906. 



