27 
and on the mountains of northern Alabama. R. carolinianum and R. 
minus are southern Appalachian species; the former is a dwarf com- 
pact shrub with leaves covered below more or less thickly with rusty 
brown scales, and compact clusters of small pure pink flowers which 
open in early spring. It grows apparently equally well in full exposure 
to the sun and in the shade of Pines and other trees. There is a white- 
flowered form with thinner, less rusty brown leaves, which is still rare 
in gardens and appears rather less hardy than the pink-flowered type. 
R. minus grows from low altitudes, as at the locks on the Savannah 
River above Augusta, Georgia, up to altitudes of thirty-flve hundred 
feet on the Blue Ridge of North Carolina. It is a shrub sometimes 
ten or twelve feet tall, with leaves covered below with glandular scales 
and pink flowers, which in northern gardens do not open until the end 
of June, and after the shoots of the year have nearly attained their 
full grov«/’th. A fine variety of this species (var. Harhisonii) from 
northern Georgia with larger flowers is not yet in cultivation. The 
two European species R. hirsiitum and R. ferrugineum are dwarf shrubs 
with small pink or carmine flowers, the former with branches covered 
with hairs and leaves glandular hispid on the lower surface, the latter 
with glabrous branchlets and leaves covered below with rusty brown 
scales. Of the two R. hirsiitum has taken more kindly to cultivation, 
at least in the Arboretum. It can grow in soil impregnated with lime. 
R. Smirnowii, a native of the Caucasus, is said to becom.e a tree some- 
times twenty-five feet high; in the Arboretum, where it is hardy, it 
is a shrub four or five feet high, with oblong, acute leaves dark green 
above and covered below with a thick, yellowish or tawny felt which 
also covers the branchlets, and protects the leaves from the attacks of 
the lace wing fly. The flov/ers are bright pink and beautiful. Of the 
hundreds of species of Rhododendron which grow in China only the 
northern R. micranthum has up to this time showed itself able to sup- 
port the New England climate. It is a straggling shrub with small 
leaves and small compact clusters of small white flowers which give to 
the plant the appearance of a Ledum. The Japanese i2. brachycarpum 
is a handsome shrub with leaves which resemble those of R. cataw- 
biense, and rather compact clusters of large pale pink or pale straw- 
colored flowers. This species, it is said, did not reach England until 
1888; it was sent to the United States in 1862 by Dr. R. H. Hall, and 
flowered in Mr. Francis Parkman’s garden in Boston a few years later. 
The original plant was presented by Mr. Parkman to the Arboretum 
where it bloomed for several years but was finally lost in transplanting. 
This hardy Rhododendron will, it is hoped, soon become common in 
gardens as Wilson has sent large supplies of seeds from Japan. Of 
these hardy species of Rhododendron the handsomest are R. maximum, 
R. Smirnowii and R. carolinianum, and for general cultivation here 
the two American species are the most desirable and the most easily 
obtained. In the next issue of these Bulletins some of the hardy 
hybrid Rhododendrons will be discussed. 
Horsechestnuts. Many Horsechestnuts and Buckeyes are now in 
bloom in the collection of these trees and shrubs on the right hand 
side of the Meadow Road. Of the European Horsechestnuts {Aesculus 
hippocastanum) it is not necessary to speak, for one of the most splen- 
