39 
called, is an old inhabitant of gardens and is a useful rock garden 
plant. The fragrant leaves are sometimes used like those of the com- 
mon Thyme in cooking. 
Philadelphus purpurascens. This Chinese species is now covered 
with flowers. It is a large, vigorous shrub with long arching branches 
from which numerous branchlets spread at broad angles and are from 
four to six inches long; on these are borne on drooping stems the 
flowers Vv^hich have a strong pungent and delightful odor, and are about 
an inch and a half in diameter with a light purple calyx and pure 
white petals which do not spread like those of many of the species 
but form a bell-shaped corolla. This is one of the most distinct and 
beautiful of all the Old World species, aud one of Wilson's important 
introductions from western Chiba. It can best be seen in the Philadel- 
phus Group on the Bussey Hill Road opposite the Lilacs. 
Philadelphus inodorus. This na,tive of the southern Appalachian 
foothill region, although the flowers are without fragrance, is for 
many persons the most beautiful plant of the genus. It is one of the 
medium-sized species with gracefully arching stems and pure white, 
cup-shaped flowers from an inch aijd a half to two inches in diameter. 
It is not often seen in gardens, although it was one of the first species 
of Philadelphus cultivated in Europe where it was first seen about the 
middle of the eighteenth century. The plants in the Shrub Collection 
and in the Bussey Hill Group are now covered with flowers. 
A double-flowered Philadelphus. A Philadelphus raised by Lemoine 
and called by him Argentina is flowering for the first time on Bussey 
Hill Road. It is still a small shrub with erect, rather rigid stems now 
covered with large semi-double flowers which look like small white 
roses. More curious than beautiful, this addition to summer-flow- 
ering garden shrubs will perhaps be ' valued by persons who admire 
floral monstrosities. 
Aesculus Harbisonii. This interesting plant which unfolds its leaves 
later than any other in this group and, with the exception of A. par- 
vifolia, is the last to flower, is now blooming near the other dwarf 
Buckeyes. Two individuals of this peculiar plant appeared here in 
1905 among a number of seedlings of A. georgiana and are believed to 
be hybrids of that species and the red-flowered variety of A. discolor, 
the two species growing together where the seed was gathered near 
Stone Mountain in central Georgia. The leaves of this hybrid are 
lighter green than those of either of its supposed parents; the flowers 
are borne on stout red stems in broad red panicles and are about three- 
quarters of an inch in length with a rose-colored calyx and canary yellow 
petals tinged with red toward the margins. The hybrid origin of these 
plants is shown by the fact that glands and hairs are mixed together 
on the margins of the petals, hairs only being found on the margins 
of the petals of plants of the group of Aesculus to which A. georgiana 
belongs and only glands on those of the plants of the group to which 
A. discolor belongs, so that when both hairs and glands are found on 
the margins of the petals of one of the Buckeyes it is good evidence 
that the plants are of hybrid origin. 
Cornua racemosa. This northern Cornel has been largely used in 
the Arboretum in roadside plantations and is now conspicuous as the 
