BROAD-LEAVED EVERGREENS 367 



green above, densely clothed beneath with close or floccose gray to brown 

 tomentum, the lateral veins not visible: flowers in 7-15-flowered heads; 

 calyx minute, pubescent; corolla campanulate, 7-lobed in the typical form 

 and 2-23^ inches across, pale to deep rosy-pink, not spotted; stamens 14. 

 Flowers in May and June. Japan. — Only the following variety is in culti- 

 vation : 



Var. pentamerum, Maxim. Flowers smaller, 13^-2 inches across, 5-lobed, 

 stamens 10. This is the common wild form in Japan and was introduced to 

 Europe about 1870 and in 1892 by Prof. C. S. Sargent to the Arnold Arbore- 

 tum where it has proved perfectly hardy. 



The related R. caucasicum, Pall, can hardly be classed among the taller 

 rhododendrons, as it does not become more than 2 or 3 feet high. It has some- 

 what smaller and thinner leaves, with the lateral veins visible beneath the 

 closer and thinner brown tomentum; the scales near the base of the leafy 

 branches are persistent and the pink to white flowers are spotted greenish 

 within. It was introduced about 1803 to Great Britain, and has played an 

 important part in the development of the hardy rhododendrons, but the true 

 species is probably not now in cultivation in this country. 



R. brachycarptim, D. Don. Shrub to 12 feet tall; young branchlets gray- 

 ish tomentose: leaves elliptic to oblong-lanceolate, 23/2~7 inches long, obtuse 

 and mucronate at apex, narrowed toward the truncate or slightly auriculate 

 base, dark green and reticulate above, covered beneath with dark gray or 

 dun-colored tomentum; petiole pubescent: flowers short-pediceled, in dense 

 clusters; calyx minute; corolla funnelform-campanulate, about 2 inches 

 across, white to yellowish-white, often flushed and striped pink, the upper 

 lobe spotted greenish or brownish; ovary brown-tomentose; style glabrous. 

 Flowers in June. Japan. — Introduced by Dr. G. R. Hall in 1861 to this 

 country. It has proved perfectly hardy near Boston. 



R. catawbiense, Miclix. Shrub to 6 feet, rarely to 20 feet tall; young 

 branclilets glabrous: leaves oval to oblong, 3-5 inches long, usually obtuse 

 and mucronulate at apex, rounded at base, dark green and lustrous above, 

 glaucescent beneath: flowers in dense clusters; pedicels rusty-pubescent or 

 nearly glabrous; calyx short; corolla broadly campanulate, 2-23^ inches 

 across, with broad roundish lobes, rosy-purple, the upper lobe spotted green- 

 ish; ovary rusty- tomentose; style red, glabrous. Flowers in June. Virginia 

 to Georgia on the higher mountains where it often covers extensive tracts. — 

 Introduced to England in 1809 by J. Eraser. Hardy as far north as Massa- 

 chusetts. This, like the following species, is now extensively used in park- 

 planting and taken by the carloads from the native woods and mountains; 

 if properly handled and taken from turfy soil with a sufficient ball of soil 

 around the roots the shrubs are usually successfully transplanted. Rhodo- 

 dendron catawbiense has played the most important part in the development 



