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only by the typical form, but by many horticultural va- 
rieties, some of them very decorative. The wood of this 
tree is valued for fence posts, railway ties, etc., and from 
its young branches fluid extracts and tinctures are made 
which are used in medicine. The Chinese arbor vitae, 
from China and Japan, has a number of specimens repre- 
senting it and some of its horticultural forms. 
The maiden-hair tree family is represented by a single 
species, the maiden-hair tree, several specimens of which 
may be found on the southern portion of the westerly ridge 
of the herbaceous grounds. This interesting tree, with its 
fan-shaped leaves, is a remarkable relic of a type of vegeta- 
tion which was common and widely distributed in tertiary 
geological time, but is now restricted to eastern temperate 
Asia in this one species, Ginkgo biloba. 
4. The Herbaceous Garden 
The collection of hardy herbaceous plants is situated in a 
valley southeast of the public conservatories, and between 
the main driveway and the western border of the woods 
fringing the hemlock grove. This valley is about 1500 
feet long and averages about 300 feet wide. A small 
stream runs through the valley from north to south and is 
here and there broadened out into pools. The collections 
are arranged in three series: (4) The systematic plantation; 
(b) the morphological garden; (c) the economic garden; 
the viticetum, or collection of vines, is planted at an 
arbor just east of the northern part of ae valley. 
(a) SysTEMATIC PLANTATION 
This is located in that portion of the valley south of the 
driveway crossing it, and here the plants are grouped by 
natural families in botanical relationship. At the southern 
end are the seedless plants, represented by the ferns and their 
allies; east of the brook are the families of seed-bearing 
plants belonging to the large endogenous division, or those 
with parallel-veined leaves and with one seed-leaf (monocot- 
