The times. [volume] (Washington [D.C.]) 1897-1901, 1901-04-28
TYPES OF AMERICAN TREES
Herbarium Adjuncts TO Various BO.
tanical Gardens.
Their Influence Upon the Work of
Acknowledgements ArrnnG-
ed to Constitute N Dictionary of
Plants Reference for students.

BOSTON. April "a herbarium is well
called library of botanical dictionaries
where actual specimens take the place Of
printed descriptions or illustrations OF
trees and plants. one Of the chief diff
culties which the student of botany en-
counters is in the great mass of synony-
nous names which have been accumu-
lating during many generations. BY ref
erence to herbariums this confusion in
botanical nomenclature is being gradually
untangled. and the Identity OF each grow
ing thing established.
There are more or less valuable herba-
RUINS connected with many botanical
gardens and prominent colleges in this
country, the Gray Northumberland in
honor of the great American botanist,
Asa Gray-at Cambridge. founded sixty
years ago. being the richest in general
types. But it is only within the present
generation that the idea of specializing
these botanical Libraries has been Sc
riously carried out an idea which. in the
herbarium at the Arnold Arboretum in
this city, devoted-like the plantations Of
the Arboretum-exclusively to trees and
other woody plants. has resulted in the
most comprehensive neurological herba-
rum in the world. Such a herba rum
lacks the variety, of course, of the INC re
general collections, but carries Colnpensa-
ton in the fact that within its limits It
can be more carefully gathered and be
made more complete.
To the casual glance the herbariUn of
the Arboreturn shows rows of plain wood
en- cases with tightly closed doors. If
these doors are opened it is seen that the
interior of the cases holds two tiers of
shelves, each containing a number of
brown paper covers folded over loose
sheets of stiff white paper Upon each
of these individual sheets. which are
about the size of the page of large die
tionary, is glued a dried specimen from
living tree or shrub. In some Instances
only tie blossoms and leaves are shown,
but whenever possible the sheet contains
blossoms, fruit, seeds, winter buds, and
bit OF branch with leaves attached.
On the lower right hand corner of the
sheet is written the name of the species
and other brief information telling when
and where it was obtained and by whom
collected. Each folded cover contains
specimens of the some species, frequently
with photographs or sketches Of the liv
ing trees, and other descriptive matter
which it is desirable to have at hand.
Many of these specimens are from the
Arboretum itself, and these bear a num-
Der referring to the card catalogue which
gives a complete history of the tree or
shrub in question. Some are called type
specimens, as being the typical or origi-
nal specimens from which the first au-
thoritative description has been made. A
large number are labeled SILVA of North
America being the types upon which
were based the descriptions contained in
that exhaustive work, which has been
the chief labor of the director of the
ArboTetum during the first twenty-five
years of its existence. 1t is largely in
the possession OF such typical specimens
that a herbarium becomes a permanent
authority for reference for botanists all
over the world.
The permanence OF a herbarium is hard
to believe. The specimens of pressed
flowers and leaves seem too fragile to last
natural records from century TO CEN
fury. yet II has been found that speci-
mems preserved in Europe for nearly 200
years are still valuable. and with proper
care are like the books in library. prac-
tically indestructible The dangers TO be /
guarded against are dampness, insects, /
and light The dampness means decay,
the attack OF insects means humiliation,
and the exposure to light means in many |
Instances fading or dtscoloration. Con-
seqUentiy. when specimen is secured, II |
is first thoroughly dried by being placed |
between sheets Of blotting paper which |
are changed at least once or twice a day. |
This process must be continued usually |
for week, although it has been learned |
by experiment that the more rapidly the |
specimen can be dried. the better its color |
Will be preserved. After all the moisture |
has been drawn out of il the specimen is |
dipped into corrosive sublimate, which |
serves to guard it against the attacks of (
insects. The destruction of many of the |
earlier herbariums by these pests has |
shown the necessity Of some such poison- |
GUS solution. whether corrosive sublimate |
or arsenic.
The cases now used are sufficiently |
tight TO keep out the light, but with all |
possible care the leaves of some families 1
of trees turn black in drying However. |
the color is Of minor Importance, as the 1
botanist In his studies depends more on |
the shape and structure of the leaves and |
blossoms and their arrangement upon the /
stem than upon shades Of color. Very
often the seeds Of the tree or shrub are /
attached TO the specimen sheet in an |
envelope. but where this il not practi-
cal BILE on account Of bulk, as in the case Of
nuts. acorns. or pine cones, they are ar
ranged systet aticaliy in boxes at the |
end of the tier of cases devoted to the
records of the family in which they are
included. Each nu. is carefully numbered |
to prevent displacement and consequent !
confusion The cones of fir trees and
the leaves of hemlock and spruce are diff |
hcult to preserve, since they are apt TO |
fall apart when perfectly dry BY care |
fully gluing the latter TO a sheet Of paper. |
however, it is possible to preserve their
general appearance in spite of this tend
ency. and with the cones the same end is
obtained by wrapping them with wire.
Palm leaves which are so large as TO be
unwieldy are preserved and studied in |
sections. In the old European hcrbari-
um l. was customary TO keep specimens
loose between folded sheets OF paper or !
10 attach them to single sheets with paper
bands. It has been found to be a better |
plan &c glue the specimens bodily to the
sheets, as they are thus more enduring
and more easily handled.
As dictionary which is arranged in !
alphaDeucal order needs no index. so a |
herbarium arranged like that at the Ar
iicaton is its own catalogue. The order |
OF arrangement is the same as that ia
me gardens OF the Arboretum proper, be-
ginning with the trees which have the
most highly developed blossoms. like mag
nelias. tulip trees. and lindens. and con
tinuing in botanical sequence to hem
locks. spruces. frs. and larches There
are index cards on the cases as "A matter |
OF convenience but just as a reader turns
al once TO the part of the dictionary he |
desires to consult, so the botanist finds
what he wants in this natural dictionary |
without appreciable loss of time
he herbarium Of woody plants at the |
arnold Arboretum belongs. like the Gray |
lierbarlum. to Harvard University. and |
represents very largely the personal work |
OF Mr.. Charles S. Sargent and others CON |
necteG with the garden during the past |
! invent y-fve years. Mr. Sargent has col
ieeted specimens from every part Of North
america north Of Mexico, and in Janan
and Europe: few botanists. indeed have |
Travelled more widely and constantly |
Many specimens have been given 10 Tho i
herharium and many others have been |
obtained by exchange with other barl,o |
RUINS both in this country and abroad
Every year three or four thousand enecf-
mems are added, and while the seventy
SIX cases probably contain in the neigh
borhOod Of 100. 900 specimen sheets M -
Ntf-F has