Coast rhododendron, or California rosebay, an erect evergreen 

 shrub, commonly 3 to 10 feet high, occasionally taller and treelike, 

 occurs on the west slope of the Cascades and in the coastal regions 

 from British Columbia into northern California. The generic name 

 Rhododendron in this case is also the common name ; it is a combina- 

 tion of the Greek rhodon, rose, and dendron, tree ; hence rosetree (or 

 rosebay). It is a very handsome plant, with large, evergreen leaves 

 crowded at the summit of the straight stems. During the spring 

 and early summer the large, showy, terminal, rose-colored flower 

 clusters are attractively displayed above the bright green leaves. 



Coast rhododendron inhabits moist, humid woods, both in open 

 and shady sites. It attains maximum development in the shaded 

 forests of the redwood region, where treelike specimens up to as 

 much as 26 feet in height are not uncommon. 1 It does best on moist 

 rich soils, but apparently is unable to survive in extremely wet and 

 boggy places. In the region where coast rhododendron grows, 

 Douglas fir is probably the most common timber species, while salal, 

 western bracken, and hazel are forest floor plants commonly asso- 

 ciated with it. 



Stockmen consider coast rhododendron negligible to worthless as a 

 forage plant for all classes of livestock. The foliage is definitely un- 

 palatable, but it is not known whether this is due to its thick and 

 leathery character or to some disagreeable taste, possibly resulting 

 from the harmful compound, andromedotoxin. 2 It has been reported 

 as poisonous to sheep, 1 although this has not been substantiated by 

 experimentation. It is highly probable, however, that the plant 

 contains poisonous properties, which are known to be generally pres- 

 ent in the eastern and Old World rhododendrons, as well as in the 

 closely related azaleas, including western azalea ( Azalea occidentalis) 

 of California and southwestern Oregon. Ho\vever, even if it were 

 definitely known that coast rhododendron is potentially poisonous 

 sickness or losses from it, under range conditions, are probably negli- 

 gible, as it is unpalatable and, for the most part, grows in regions not 

 grazed by domestic livestock. It is, perhaps, worth while to mention, 

 in this connection, that honey made from rhododendrons has the rep- 

 uation of producing a violent purgative and emetic effect. 



Coast rhododendron is frequently cultivated as an ornamental, 

 evergreen, acid-soil shrub. It is the only true Rhododendron, grow- 

 ing in the Western States, unless the opinion of certain western 

 botanists is accepted that western azalea and false-azalea (Azale- 

 astruni albiflorum) also belong to the genus Rhododendron. These 

 last-named two species are actually quite different from coast rhodo- 

 dendron. Western azalea is a deciduous, thin-leaved shrub, having 

 somewhat larger, white, or pink flowers, with the five stamens extend- 

 ing about an inch beyond the corolla (united petals). False-azalea is 

 a smaller shrub, with leafy stems, deciduous leaves, and white, 10- 

 stamened flowers borne in lateral clusters. 



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

 Berkeley, Calif. [1925.] 



2 Chesnut, V. K. PRELIMINARY CATALOGUE OF PLANTS POISONOUS TO STOCK. U. S. Dept. 

 Agr., Bur. Anim. Indus. Ann. Rept. (1898) 15 : 387-420, illus. 1899. 



