B150 

 (leaf 2) 



variety of conditions than most cultivated shrubs. Various species are in local 

 repute as medicinal plants; the eastern hardback (8. tomento'sa), for example, 

 which is bitterish and has astringent properties, has been used locally in New 

 England as a tonic, and was undoubtedly similarly employed by the Indians. 

 The spireas have some value in erosion control on the western mountain ranges, 

 especially those species with creeping rootstocks which are able to spread out 

 and thus effectively bind the soil mass, 



Subalpine spirea (8. densiflo'ra, syns. S. arbus'cula, 8. hel'leri), Douglas 

 spirea (8. douyla' sii) , birchleaf spirea (8. lu'cida, syn. 8. corymbo'sa- lu'cida), 

 and Menzies spirea (8. menzie'sii), are probably the most widely distributed 

 and common spireas in the West. 



Subalpine spirea, as the name indicates, is most common in the siubalpine 

 zone, extending from British Columbia to California, Wyoming, and Montana. 

 This shrub is often associated with western white pine and lodgepole pine, 

 but prefers rocky situations, commonly growing in the soil-filled cracks of the 

 rocks. It ,is a low (at most, up to 3 feet) much-branched shrub, the stems 

 sometimes being crooked, with dark, red-brown bark. This species ordinarily 

 occurs as individual plants, but sometimes also grows in clumps; it is 

 of negligible forage value. The dense, flat-topped flower clusters are an 

 attractive red in tint. 



Douglas spirea, a shrub from 3 to 8 feet in height, with straight, erect steins, 

 is distributed from British Columbia to northern California, chiefly in the 

 coastal region. It occurs characteristically in patches or thickets often cover- 

 ing several acres along creek bottoms, meadow borders, moist flats, and in 

 cut-over Douglas fir lands. The upright, leafy stems grow a few inches to a 

 foot or more apart, and are sparingly branched above the middle ; the leaves 

 are woolly beneath. The flowers are rose-colored, and aggregated into dense, 

 pyramid-shaped clusters at the ends of the stems and twigs. Although often 

 abundant on the ranges, it is of negligible value, ordinarily being consumed 

 only where forage is scarce, as on depleted areas, or during the fall. 



Birchleaf spirea, a white-flowered species, occurs from British Columbia to 

 Oregon and east to Wyoming, South Dakota, and Saskatchewan. An upright, 

 little-branched shrub, 1 to 3 feet in height, which develops from creeping root- 

 stocks, it differs from the other common western spireas in its relatively large, 

 birchlike leaves, and dense, flat-topped, white flower clusters. On the sterile 

 twigs the smallest leaves are usually at the base and the largest leaves at the 

 tip. On the flowering twigs the same tendency is observed but, as is so often 

 the case, the leaves immediately subtending the flower clusters are reduced 

 in size. It inhabits open hillsides and dry woods, and, although sometimes 

 abundant in the Northwest, its forage value is negligible. 



Menzies spirea, which grows from Alaska to Oregon and east to Idaho, re- 

 sembles Douglas spirea, except that it is smaller (3 to 4 feet high), and has 

 thinner and smooth leaves. The pink or red flower clusters are similarly pyram- 

 idal but rather narrow. It usually grows in the sunlight or shade along 

 streams and similar sites, and is sometimes locally abundant. Menzies spirea 

 is perhaps the most palatable of the spireas on the western ranges, rating in 

 the Northwest as fair to good in the fall for both cattle and sheep. 2 



The spireas are closely related to the ninebarks (Opulaster spp., syn. Physo- 

 carpua spp.) and to the rockspireas (Seriootheca spp., syn. Holodiscus spp.) ; in 

 fact, many of the species in these two genera were at one time included in 

 the genus Spiraea. Like the spireas, they are deciduous shrubs, with simple 

 leaves and usually numerous small flowers crowded into terminal, sometimes 

 very showy, clusters. The chief differences are that the leaves of ninebarks 

 are three-lobed, the bark shreddy, the flowers mostly white, and the pods usually 

 inflated. The rockspireas have toothed or lobed leaves, white flowers, and the 

 "seeds" (achenes) are long-hairy. 



2 Dayton W A IMPORTANT WESTERN BROWSE PLANTS. U. S. Dept. Agr. Misc. Pub. 

 101, 214 pp., illus. 1931. 



