near relative from eastern Siberia, Aralia mandshurica, still sometimes 
found in nurseries under the name of Dimorphanthus. The Hercules’ 
Club grows sometimes thirty feet high, with a slender stem armed like 
the branches with stout prickles. The leaves are twice pinnate, from three 
to four feet long, and two and a half feet wide, and the small white flowers 
are borne on long slender stems in many-flowered clusters arranged in 
broad twice compound panicles three or four feet in length, rising singly 
or in pairs above the spreading leaves. The flowers are followed by 
great clusters of small black fruits which ripen in the early autumn. No 
other tree of temperate North America has such a tropical aspect as this 
Aralia, which is not always entirely hardy in New England although it 
is now well established at the northern base of Hemlock Hill, just back 
of the Laurels, where it has spread by suckers from the roots. Its Man- 
churian relative, which greatly resembles the American tree, is hardier 
here and can be seen in the border between the drive and walk next to 
the Liquidambars and in the Aralia Group. 
Another North American tree, the sorrel-tree or Sourwood, Oxyden- 
drum arboreum, is now covered with flower-buds. This beautiful and 
interesting tree belongs to the Heath Family and is the only repre- 
sentative of its genus. On the rich slopes of the southern Appalachian 
Mountains it sometimes rises to a height of thirty feet or more, although 
in cultivation at the north it begins to flower when only a few feet high 
and will probably never become a large tree. The leaves are oblong, 
bright green and very lustrous, and have a pleasant acidulous flavor to 
which this tree owes its common names. The white flowers, which are 
shaped like those of the Andromedas, are erect on the branches of a ter- 
minal, spreading or slightly drooping, compound cluster seven or eight 
inches long; they retain their beauty for a long time and are followed by 
capsular fruits. The leaves of this tree turn in the autumn bright scar- 
let. The Sorrel-tree appears to be free from the attacks of all insects; 
it does not suffer from disease, and it is surprising that such a handsome, 
hardy and interesting tree should be so little known. There are a num- 
ber of individuals among the Laurels at the northern base of Hemlock 
Hill. 
With the early flowering Japanese forms of Hydrangea paniculata 
(var. praecox) mentioned in a recent Bulletin, Aesculus parviflora is now 
the most conspicuous shrub in flower in the Arboretum. This native of 
the southeastern United States is the last of the Horsechestnuts to flower. 
It is a shrub which in cultivation sometimes spreads to a diameter of 
twenty feet or more but rarely attains a greater height than six or eight 
feet. It is a good plant to use as a single specimen as it is perfectly 
symmetrical in habit, or, as has been done in the Arboretum, it can be 
planted in masses. The plants are now covered with long narrow spikes 
of small creamy white flowers which stand erect above the dark 
green foliage. A group of this Horsechestnut can be seen with the other 
Horsechestnuts on the right-hand side of the Meadow Road at the base 
of the woody hill which rises at the southwestern extremity of the north 
meadow. 
The Pepperbush, Clethra alnifolia, will soon open its fragrant white 
flowers which are borne in erect, terminal, compound clusters. This is 
perhaps the most beautiful of the summer flowering shrubs of New Eng- 
land and is a common inhabitant of swamp borders and other wet places 
in the neighborhood of the coast from Maine to Florida. The Pepper- 
bush can be seen along the Meadow Road where it has been largely 
planted, and in the Shrub Collection. A form with flowers faintly 
