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and there is no better shrub to plant by the margins of ponds and 
streams where its long branches can hang gracefully over the water. 
Its purple stems are attractive in winter, and the bright blue fruits 
which ripen in the autumn add to the value of this native shrub. Its 
value and beauty as a water-side plant can be seen at two of the small 
ponds near the end of the Meadow Road. 
Cornus paucinervis, introduced by Wilson from China, is the last of 
the Dogwoods to flower in the Arboretum, It is a shrub now six or 
seven feet tall with erect stems and short spreading branches, small, 
narrow pointed leaves with only two or three pairs of prominent veins, 
small clusters of white flowers and black fruit. This shrub grew and 
flowered well for several years in the Arboretum but was badly injured 
by the exceptional cold of the winter of 1917-18; it has partly recov- 
ered and the plant in the Chinese collection on the southern slope of 
Bussey Hill is now covered with flowers. A native of low level lands 
in central China where the Orange flourishes and rarely ascending to 
altitudes of three thousand feet, it is not surprising that the New Eng- 
land climate is too severe for it. Further south Cornus paucinervis 
should be a valuable summer-flowering shrub. 
Calluna. There is a good collection of the varieties of the Scotch 
Heather {Calluna vulgaris) in the Arboretum and the bright crimson 
flowers of the first of them to bloom here (var. rubra) are already 
open. The flowers of some of the white-flowered varieties are begin- 
ning to open and for several weeks now the different Heathers will be 
an interesting feature of the Shrub Collection. It does not appear to 
be very generally known in this country that the European Calluna is 
hardy in northeastern North America, where it has become naturalized 
near the northern border of Massachusetts and in Nova Scotia. On 
one Massachusetts estate where it was planted only a few years ago 
it has spread over several acres, and in late July or early August 
makes a great show. Calluna should be planted in not too rich, thor- 
oughly drained soil and in full exposure to the sun. The ends of 
branches are sometimes killed in winter but this does not do the plants 
permanent harm; and the advantage of the severe pruning of the old 
wood the plants receive in early spring before they begin to grow is 
seen in the compact habit and abundant bloom of the plants in the 
Arboretum collection. Unless they are so pruned the plants become 
thin and bare of leaves, and are often short-lived. 
Philadelphus argyrocalyx. This handsome plant has flowered this 
year for the first time in the Arboretum where it is established in the 
Shrub Collection. A native of the southwest, the Arboretum plants 
were gathered in 1916 by Mr. Alfred Rehder on the Sacramento Moun- 
tains, New Mexico, at altitudes of eight thousand five hundred feet. 
It is a small shrub with small elliptic leaves. The flowers are solitary, 
an inch across, and the calyx, like the lower surface of the leaves, 
is covered with a thick mat of snow white hairs. It flowers late, at 
the same time or only a little earlier than the hybrid Philadelphus 
insignis which blooms later than any other Philadelphus in the Arbor- 
etum collection. 
These Bulletins will now be discontinued until the Autumn. 
