8 
Prinsepia sinensis is again covered with clusters of bright yellow 
flowers which spring from the axils of the half-grown leaves. This 
Prinsepia is a tall broad shrub with long spreading and arching branches, 
and stems armed with many spines. It is perfectly hardy and the 
handsomest shrub Manchuria has contributed to western gardens. 
There are only two specimens in the Arboretum and these came here 
from Petrograd in 1903 and 1906, and it has been found difficult to 
propagate them by cuttings. Fortunately last year one of the plants 
produced for the first time a few seeds and these have germinated, 
so there is reason to hope if the Arboretum plants become more fruit¬ 
ful that this species will be a common ornament in northern gardens. 
It has much to recommend it as a hedge plant. The species from north¬ 
ern China, P. uniflora, is a spiny shrub with small white flowers, and 
although it has little beauty its value for forming impenetrable hedges 
may prove considerable. 
Primus dasycarpa, which is sometimes called the Black Apricot from 
the dark color of its slightly downy fruit, is the first of May one of 
the handsome flowering trees in the Arboretum. It grows here both 
as a great round-headed shrub with several stems or as a tree with a 
single trunk, and every year is completely covered with its flowers 
composed of pure white petals and a bright red calyx. This tree, al¬ 
though it has been known in European gardens for at least a century, 
is apparently extremely rare in the United States. Its origin is doubt¬ 
ful; it has been considered a native of Siberia, but it is now generally 
acknowledged that it is a hybrid between a Plum and an Apricot. 
Although this tree has been growing in the Arboretum for twenty 
years, there is no record that it has produced fruit here on more than 
two occasions. 
Two Useful Shrubs. Two plants useful for covering the margins of 
drives and the borders of shrubberies, Rhus canadensis {aromatica) and 
the Yellow Root {Xanthorrhiza apiifolia) are covered with flowers. 
Those of the former are small, pale yellow, arranged in compact 
heads, and appear before or with the unfolding of the leaves composed 
of three leaflets; those of the Yellow Root are purple in long droop¬ 
ing, terminal racemes. The flowers of these two eastern American 
plants are attractive, but their great horticultural value is in their 
habit of growth. The height of the Rhus is from two to four feet, 
with spreading branches, the lowest flat on the ground, and with an 
irregular top. In the autumn the leaves turn bright scarlet. For road 
borders and to plant when it is desirable to make a connection between 
larger shrubs and the ground no other plant which has been tried here 
has proved so successful. The Yellow Root is a dwarf shrub which 
soon spreads over a wide border and forms with its erect stems and 
divided leaves an excellent ground cover. Unfortunately it has failed 
to grow well in those parts of the country where the soil is strongly 
impregnated with lime. 
