43 
show of flowers and fruits, and the numerous Elders sown by birds on 
the banks of the Bussey Brook in the valley north of Hemlock Hill, 
and by the little ponds near the junction of the Meadow and Bussey 
Hill Roads add much to the beauty of the Arboretum in July. Grow- 
ing with Sambucus canadensis in the Shrub Collection is a form with 
leaflets deeply divided into narrow segments (var. acutiloba) and more 
curious than beautiful. There are here also a form with yellow fruit 
(var. chlorocarpa), and var. maxima, which originated a few years ago 
in a European nursery and which has flower-clusters three times as 
large as those of the wild plant and such large and heavy bunches of 
fruit that the branches can hardly support them. A variety w’ith 
yellow leaves (var. aurea) is also in the collection. More objectionable 
than many yellow-leaved shrubs because it is hardier and grows more 
rapidly to a larger size than some of them, this plant now disfigures 
many European gardens and is too often seen in those of this country. 
Zelkova serrata, or, as it is more generally known, Z. keaki, Keaki 
being the Japanese name for this tree, is one of the important trees 
of Japan. Although no longer very common or of a large size in the 
Japanese forests, it is one of the largest of Japanese trees, for speci- 
mens one hundred feet high with trunks from eight to ten feet in 
diameter are not uncommon in temple gardens and by village roadsides. 
The wood is more valued by the Japanese than that of any other tree; 
it is tough, elastic and durable both in the ground and when exposed 
to the air, and is considered the best building material in the empire. 
Keaki, however, has now become so scarce that it is not used for build- 
ing except in temples in vrhich the large, round, light brown, polished 
columns which support the roof are always made of this wood; it is 
universally used in the manufacture of jinrikishas, and it is still much 
employed in cabinet-making and turnery. Zelkova is a genus related 
to Ulmus. The leaves resemble those of some of the small-leaved 
Elms; the male and female organs, however, are in separate flowers 
on different parts of the branch; the fruit is a small drupe, and the 
bark is more like that of a Beech-tree than of an Elm-tree. The Keaki 
is probably worth general cultivation as a timber tree in some parts 
of the United States. That it can flourish here at least for many years 
is shown by the trees planted in Warren, Rhode Island, in 1862, by 
the late Dr. George R. Hall. Thirty years later these trees were fifty 
feet high with trunks a foot in diameter, and were producing large 
crops of seeds from which seedling plants were growing spontaneously 
in large numbers. Two of these seedlings can be seen in the Arbore- 
tum in the Celtis Group on the slope below the right-hand side of the 
Bussey Hill Road above the group of Sassafras trees. Here may be 
seen, too, a young plant of the Caucasian species, Z. crenata. This has 
been a difficult plant to establish in the Arboretum but there is a pic- 
turesque old specimen in the Harvard Botanic Garden. 
Hemiptelea Davidii. Specimens of this interesting tree from north- 
ern China, known as the “Prickly Elm,” are established in the Celtis 
Group and larger specimens can be seen in the nursery near the top 
of Peter’s Hill. In foliage this tree also looks like a small-leaved 
Elm but the branches are furnished with sharp thorns. The flowers 
are similar to those of the Zelkova, but the fruit is slightly winged 
and distinctly short stalked. Of no particular value as an ornamental 
