The times., 1901-04-28
TYPES OF AMERICAN TREES
Herbarium Adiuncts TO Various BO-
taniCal Gardens.
Their Influence Upon the Work of
ArboricuItgre-Spe ATTnRg
ed to Constitute Dictionary Of
Plants Reference for students.


BOSTON. April IA herbarium is wei
called a 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
untangIed. 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 botanst,
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 cut, 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 herbarium
lacks the variety, Of course, of the aCre
general collections. but carries Colnpenaa-
tion in the fact that within its limits It
can be more carefully gathered and be
made more complete.
To the casual glance The herbarium Of
the Arboretum 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
gha 0f
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 a large die
tionary, is glued 4 dried specimen from
living tree or shrub in some instances
only the 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 orisi-
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
We're based the descriptions contained in
that exhaustive work which has been
the chief labor of the director Of the
Arboretum during the first twenty-five
years of its existence. It 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 q heFbarium is hard
to believe. The specimens Of pressed /
flowers and leaves seem too fragile TO last
as natural records from century TO cen
Jury. get IL has been found that sDecl- /
mems preserved in Europe for nearly 200 /
years are still valuable, and with proper /
care are like the books in a library. prac- 4
Iically indestructible. The dangers 10 be (
guarded against are dampHess, insects, I
and light. The dampness means decay, /
the attack OF insects means annihDauon, I
= nd the exposure to light means iu many 4
Instances fading or discOioTatlon Con /
seqUentiy. when a specimen is secured, il 1
is first thoroughly dried by being placed !
between sheets of bl0ttinE paper which 1
are changed at least once or twice s. day. /
This process must be continued usually /
for week. although it has been learned /
specimen can be dried. the better its color 1
VIII be preserved. After all the moisture /
has been drawn out Of it the specimen is !
dipped into corrosive suBllmaIe, which /
serves to guard it against the attacks Of {
insects. The destruction Of many OF the /
earlier heTbariums by these pests has /
oUs solution, whether corrosive sublimate
or arsenic.
The cases now used are sufficiently 1
tight 10 keep out the light, but with all /
possible care the leaves of some families /
OF trees turn black in drying. However |
the color is Of minor Importance, as the /
botanist in his studies depends more on
the shape ana structure or 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
TO the specimen sheet in an !
but whore this is not practi-
able, on account of bulk as in the case Of
nuts. acOras. OF pine cones. they are ar 4
ranged sysret aticalIy in boxes at the
end Of the tier Of cases devoted to the
records Of the family in which they are |
included. each nut is carefully numbered /
To prevent misplacement and consequent J
CONFUSION. The cones of FIR trees and }
the leaves Of hemlOck and spruce are diff 4
hcult to preserve. since they are apt 70 I
tall apart when perfectly dry. BY care
fully gluiug the latter 70 "A sheet Of paper /
however. II IS possible TO preserve their !
general appearance in spite Of this tend !
encF. and with the cones the same end is |
obtained by wrapping them with wire ,
Palm leaves which are so large as to be I
are preserved ana studied ia
sections. In the old European hrrbari-
um j. was customary TO keep sUecimeus |
loose between folded sheets Of pa per. or !
10 attach them 10 single sheets with paper
bands II has been found 10 be q better I
plan 70 glue the specimens bodily to the |
sheets. as they are thus more enduring
and more easily handled.
As a dictionary which is arranged IN !
alphabetical order needs no index. so a |
iierbarlum arranged like that at the Ar
DOretuIn according to q scientific cIaSsi- |
leation is its own catalogue THE order |
OF arrangement is the same as that ia /
Lne gardens Of the ArDoretum urOTer he
ginning with the trees which have the !
most highly developed blossoms. like mag
noiias, tulip trees. and lindeus. and con
llnuing IN botanical sequence to hem /
locks. spruces. Hrs. and larches. There !
are index cards on the cases as 4 matter !
1I convenience, but just rs a reader turns !
al once 10 the part Of the dictionary he /
desires TO consult. so the botantst finds !
what he wants in this natural dictionary |
without appreciable loss Of time
: ne herbafIum Of woody plants 81 the |
AIhoId ArOOretum belongs. like the GRAY |
lferbarium. 10 Harvard University. and
Tepres nts very largely the personal work
Jt A4f- tharieS >. Sargent and others CON |
1ected with the garden during the past
twenty-five years. Mr.. Sargent has coil
ected specimens from every part Of North
america north OF Mexico. and Ia Japau
ana europe; few botausts indeed have
Many specimens have been given 10 tLo
lerHaflum and many others have Gean
1DtslHed by exchange with other Earf4- /
tuIhs Dpth IN TINS country and abroad !
livery year lhfee or four thousand sDcci- |
mems are added, and while the seventy
Goa J..