WOODY PLANTS FOR NEW ENGLAND 53 



most unsatisfactory Lombardy Poplar. Despite the belief that it is tender, 

 there is a fine specimen of some forty feet or more luxuriating on a moist slope 

 in Topsfield, Massachusetts. Then, too, small plants of but a few feet in height 

 have in recent years withstood sub-zero temperatures successfully. 



QUERCUS VELUTINA BLACK Oak 



A quick-growing, thick-boled, native, deciduous tree of gravelly soils. In 

 maturity it becomes an open-headed, hundred-foot specimen of value in natural 

 plantings. Its blunt-lobed, dark-green leaves turn orange or dull red in 

 autumn. 



Raspberry — See Rubus 



Redbud — See Cercis 



Rhamnus Frangula GLOSSY BUCKTHORN 



A small, deciduous tree or large shrub which can add interest to roadside or 

 natural plantings in the open because of round, dark-green, shiny foliage, and 

 clusters of red fruits turning black upon ripening in late summer. Its foliage 

 is clear yellow in autumn. Larger leaves and fruits may be had by securing 

 the var. latifolia. Fruits interesting to birds. 



Rhamnus pumila DWARF BUCKTHORN 



A round-leaved, black-berried, deciduous shrub which, because of its pro- 

 cumbent branches, is suitable for the large rockery. 



RHODODENDRON 



With its hundreds of species and thousands of garden hybrids, most of which 

 are not hardy throughout New England, this genus very nearly defies tabloid 

 treatment. Nevertheless, an attempt is here made to evaluate those forms 

 which have found general favor within the area under consideration. Such 

 conservative treatment can be made, however, with no sense of finality because 

 undoubtedly some of the newer Asiatic species and varieties may prove their 

 worth for general culture in the warmer sections near the sea. Numerous 

 forms are now under test, promising among which are the hybrids of R. 

 Fortunei. Then, too, unmentioned here are many other horticultural varieties 

 based on floral color, or similar features, attractive to varying personal taste. 

 For purposes of indexing, the evergreen Rhododendrons, the deciduous Azaleas, 

 and the intermediate R. mucronulatum are not listed separately. Such horti- 

 cultural differences are, however, explained in the text. 



RHODODENDRON, ALPINE ROSE HYBRIDS 



The plants in this group are hybrids of the European R. ferrugineum and 

 R. hirsutum with various other species. Though when happy they will grow 

 up eventually to be neat, four- or five-foot, evergreen plants, their compact 

 habit makes them adaptable for culture in the larger rock garden, x R. 

 arbutifolium, three-inch leaves and pinkish-lilac, three-quarter-inch, bell- 

 shaped flowers in June; x R. laetevirens (R. Wilsoni), magenta-rose 

 flowers about twice the size of those of R. arbutifolium, June and July; x 

 R. myrtifolium, plant somewhat more vigorous, leaves slightly shorter and 

 brown beneath, flowers lilac-pink and medium-sized for the group. 



RHODODENDRON ARBORESCENS SWEET AzALEA (SMOOTH AzALEA) 



Unlike the later flowering R. viscosum, this hardy, native, deciduous shrub 

 is an upland plant which in the wild sometimes reaches a height of twenty 

 feet. The one- to two-inch, heliotrope-scented, white flowers of the type plant 



