Herbarium issues

scott meissner smeissne at 3B2ADM.MCKENDREE.EDU
Sat Sep 23 21:02:47 EST 1995

I have copied and sorted some of the advise I have gotten in
response to my inquiry last week on how to take care of a
herbarium and to let others know what is in the collection.
Just in case folks want all the advise in one file.

Thanks for all the feedback and contacts.  :)

*  One reference you probably should get is "The Herbarium
Handbook" (ISBN 0 947643 45 1) put out by authors from the Royal
Botanic Gardens, Kew.  It is soft-covered, and I believe sells
for L20 sterling.  It covers a lot of your questions.  Another
source: try doing a search of the internet (in Netscape,
etc.) of Herbarium.  Several pop up, and have background,
databases, pictures, the works.

*  the first thing you should do is have your department purchase
a copy of the _Herbarium Handbook_ put out by Kew.  Many of your
questions will be in there.

>>       *What insecticides/fungicides are
>> good for treating new specimens?  The
>> cabinets are in a lecture room so I would
>> prefer to use items that are not extremely
>> toxic to humans.

*  Some people place specimens in a microwave, which certainly
kills insects, but it also makes the specimens unusable as
potential sources of molecular material.  If you must use an
fumigant in the cases, naphthalene is best.

*  The most common method of "fumigation" now is freezing in a
home type freezer.  Bundles of specimens are placed in a plastic
bag, the bag sealed, and the bundle placed in a chest or upright
freezer for several days.  At the end of that time, the bag
(sealed) is left at room temp for several days (usually 7-10), to
allow any eggs to hatch, then refrozen for 3-4 days, and refiled.
If you've got a decent-sized freezer, you can do half a case at a

Monitor the collection at least once a month for signs of insects
and for "frass" (insect droppings).  The Solanaceae, Lamiaceae
(Labiatae) and Asteraceae(Compositae) are particularly good
places to look, as those families seem prone to damage.

There are also pheromone traps available for many of the common
herbarium pest species; place these in the case or around the
case, and you can monitor that way.

*  Here at Miami, and at many other herbaria, ultracold freezers
are the method of "fumigation".  We use a small cabinet ultracold
which is just large enough to hold herbarium sheets, and put the
material in for 48-72 hours, if there are no evident
infestations.  In bad bug situations, I sometimes leave the
specimens in for a week.  Some people recommend freezing for 48
hours, taking the specimens out for 24 hours, and then putting
them back in for another 48 hours.  I have not done that, and we
have had no bug problems since we started with freezing as our
sole means of fumigation.

We also use naphthalene flakes in the cabinets, since it is very
humid here, and this seems to keep the bugs out.

*  We have a lot of herbarium cabinets in our lab and we
generally put PDB (para dichlorobenzene- like mothballs) in them.
One of the best things to do is freeze newly acquired stuff (over
night in a -20 or a -80 if you have access). Dermestid beetles
are big culprits- watch out for them- but freezing takes
care of them.

*  We use para-dichlorobenzene (used as moth cakes in closets)
in hanger dispensers which work good in the Lane herbarium
cabinets with rubber seals around doors.  We get essentially no
odor in the lab when the cabinets are closed.

*   If your herbarium has a drying cabinet for
specimen preparation (where you put the press
with fresh specimens), I recommend putting new
specimens in there for a few days to make sure
the new specimens are completely dry, and also
to heat-kill some of the "critters."

If you are sure of infestation, one could use
a light spray of malathion, but I would do that
in a standard chemical exhaust hood in a chem

In the herbarium cabinets, most people put moth
balls (paradichlorobenzene) to prevent moth larvae
and relatives from feeding on the dried specimens.

*  I've used Shell-No Pest strips to stop a dermestid infestation
and now use mothballs.  If seals on doors are good you can't
smell the mothballs until you open them.  If you have a pest
problem you may also want to freeze all in a -40C freezer for
several days

>> Is there an online list of herbaria?

*  There are several www sites that have on-line information
about plants and herbaria.  Here are a few addresses:


*  There are certainly ways to get such lists on the net!  I am
not in contact with the herbarium people, but there is a large
group of them in the Association of Systematic Collections, 730
11th St., NW, Second Floor, Washington, DC 20001-4521.  ph. (202)
347-2850.  If they are contacted they may be able to help.

*  I don't have a good answer to your question, but here
is a WWW URL that is really neat for looking up things
botanical on the internet:


Maybe you can set up your own herbarium WWW site?!

*  We use DBase (Version III I believe) as a database for
retrieval of specimens.  Labels can be entered in DBase as data
and the fields arranged to form herbarium labels which can be
printed out as each new specimen is added.  One can sort by
family, genus, etc.  I am not sure how one would make this
accessable to Internet aside from simply printing to a
wordprocessor and making this file available through a
homepage on Netscape or similar WWW system.

*          You can put your collection on the WWW directly and
broadcast to the major search engines and biology info centers of
the WWW.

*  Herbaria, esp. small ones, are normally not databased, but
simply filed in some order that you've a prayer of finding the
specimens you want again (vbg).  Normally, that's by filing the
species alphabetically within genera, the genera alphabetically
by family, and the families alphabetically within the cases.
Commonly there are groupings of related plants as separate
collections:  fungi; mosses and liverworts; ferns and "fern
allies"; gymnosperms; angiosperms.  It's also very nice to have a
"local flora" collection with sheets representing the common
plants of the area separate from the main collection.  This will
save a lot of wear and tear on most of the specimens, and they
can be used for teaching, too.  Student specimens are fine for

How to db a collection, and formats, etc. are "hot topics" among
herbarium people.  I wouldn't invest much time in this until
you've talked to the big shots in this area.

>>       *There are some specimens that are from
>> locations I do not have keys for.  I am using
>> Gray's manual of Botany for eastern plants, and
>> I also have Gleason and Cronquist.  Could someone
>> recommend a good key for central and western flora
>> of the US?

*  I've been in the northeast too long to help with
western flora.  I would note however, that you cannot
find complete agreement between the two manuals you
are using.  Sometimes it is best to use only one
source and stick with it.

*     Gleason and Cronquist work well out here in MN.  For the
Great Plains try the Flora of the Great Plains and for the
Rockies there is the Intermountain Flora series.  You might also
want to check out Kartez and Kartez's synonamized check-list.
Flora of N.A. that is now coming out may also be good but could
take a while.

*  A great Flora for the Pacific Northwest is by Hitchcock and
Cronquist...  it's the best key I've ever used, though I don't
know if it's any use to you.

*  Try using the Flora of the Great Plains or the Flora of Texas
for central US, and the revised Jepson Manual for California.
Hitchcock & Cronquist wrote a flora of the Pacific northwest
which is also very helpful.

*  For my money, the best choice for the eastern/central US is
still New Britton and Brown Illustrated Flora of North America,
c. late 1950's, and out of print.  Pray your library has a copy;
if not, get one (3 volumes!) on interlibrary loan, and have a
work-study student photocopy it, and get it bound.  The
illustrations are priceless when you're working with a group you
don't really know; you can then update the nomenclature by
comparing to Gleason and Cronquist and Gray's.

Jones' old flora of Illinois is also quite useful, as is
Steyermark's Flora of Missouri, and Flora of the Great Plains.
Only the Great Plains is still in print.  Moving further west,
Flora of the Front Range is good for Colorado, and a combination
of the old Munz Flora of California and the revised Jepson Manual
for CA.  For the Pacific NW, there's the 3 or 4 volume Abrams
set, and then the incomplete flora of the Great Basin.

Most of the recent efforts have gone into the Flora of North
America series, of which there are two volumes released (the
introductory volume, and the first volume on ferns and
gymnosperms).  Oxford? Cambridge? Univ. Press is putting them
out, and I think they sold the first two at an introductory price
of $75/volume, reg. $150. More to come, but not yet out.  That
one is one that your department or university library should buy,
most definitely.  That will be a classic when finished.

*  For Illinois, the standard identification manual is:
Robert H. Mohlenbrock. 1986. Guide to the Vascular Flora of

Thanks again for all the advise.

Scott T. Meissner
Division of Science and Mathematics
McKendree College
701 College Road
Lebanon, IL  62254
smeissne at a1.mckendree.edu

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