44 
the first of July. The first Lilac flower, that of Syringa hyacinthiflora, 
opened here this year on the second of May. The season of Lilac flow¬ 
ers therefore extends here during fully two months. Fifty years ago 
when the Arboretum was begun the people of Massachusetts were able 
to enjoy the bloom of Lilacs only during a week or ten days. 
Late Flowering Hawthorns. Different species of Hawthorn have been 
flowering continuously in the Arboretum since the early days of May 
and the last of these are now in flower. One of the last, C. tomentosa, 
the type of the Macracanthae or as it has often been called the Tomen- 
tosae group and one of the species known to Linnaeus, is a small tree 
widely distributed from the valley of the Hudson River westward and 
southward, with large pointed leaves, small flowers in compact clusters, 
and small oblong red fruit, translucent when fully ripe. As an orna¬ 
mental plant this species is much less attractive than many of the other 
plants in this group. The Washington Thorn, so-called, Crataegus 
Phaenopyrum, probably still better known as C. cordata, is now in 
flower. It is a slender tree growing under favorable conditions to a 
height of from twenty-five to thirty feet. The dull green leaves are 
nearly triangular in shape, not more than two inches long and an inch 
and a half wide and in the autumn turn bright scarlet. The flowers 
are creamy white, smaller than those of most Hawthorns, and are 
arranged in small compact clusters. Few if any of the American species 
have less attractive flowers. The fruit, too, is small, barely more than 
a quarter of an inch in diameter; and the Washington Thorn owes its 
value as a garden plant to the brilliancy of its autumn foliage and to 
the beauty of its abundant fruits long persistent on the branches. A 
century ago Crataegus Phaenopyrum was much used as a hedge plant 
in the middle states, although there are many other American Haw¬ 
thorns which are better suited to form handsome and impassable hedges. 
It has generally been supposed at the Arboretum that C. Phaenopyrum 
was the last Hawthorn to flower here, but this year C. Chapmanii has 
flowered a few days later. This is a native of river banks in the south¬ 
ern Appalachian Mountain region and in southern Missouri and is an¬ 
other member of the Macracanthae group. It is a larger and hand¬ 
somer tree than C. tomentosa with shorter obtuse obovate leaves, flow¬ 
ers with only from five to ten stamens, and globose fruit. 
