multi-part lesson plan was developed by Gregory Shenk of the Greater
Hartford Academy of Math
and Science in Hartford. Students first collect plant specimens and
mount them so they can be preserved in perpetuity for research and
education. Then they will become familiar with using online herbarium
data and will respond to questions about the meaning of the information
they find in the "Virtual Herbarium."
I – Making collections
the 1800s and into the mid-1900s, academic
institutions of all sizes used to maintain collections of preserved
as sources of material for use in the classroom and research. In fact, it was not uncommon for individuals
to maintain private collections for their own study and leisure. With the dawning of the molecular revolution,
changes in the culture of biological research have led to an increasing
emphasis on experimentation and data collection in a laboratory
environment. One of the unfortunate (and
unintended) consequences of this shift has been a slow decline in the
and quality of biological collections at many institutions. Fortunately, collections at some of the
larger institutions have been able to survive and in some cases even
expand. The University of Connecticut
is one such institution.
Much of the
expansion of collections at
has been a consequence of
absorbing the collections from many smaller institutions as they made
more technically oriented biological science programs.
There can be a great deal of valuable data
recorded with these specimens and many questions can be answered using
data. In order to keep the data
up-to-date, new collections need to be made and archived.
organisms of all kinds can be
collected and preserved
for long-term storage, this exercise will focus on botanical
collections. You will be expected to
identify and mount a collection of 15 plants.
Your collections will be submitted to the herbarium at the University of Connecticut and will become part
collection that is available for researchers around the world to use. Your name and the name of your institution
will appear on collection labels so students half a world away may one
using your collections in their own research!
a location where you would like to collect plants and obtain permission
the landowner and collection permits (if applicable).
You should have a notebook to record field
data on your specimens, a trowel for digging out plants by the roots
pruners for collecting woody branches. You
will want to record as much information in your notebook as possible at
time of collection (see label below to see what you will want to
record). You needn’t identify the plant
(but it won’t
hurt) at the time you collect each specimen, but you should record the
collection number, the date collected, and a description of the
the plant was collected. The collection
number for each specimen is unique and most collectors start at 1 (so
with four- and five-digit collection numbers reveal a collector who has
very busy!). The date is very important
as the developmental stage of the plant at the time when collected may
changes in environmental conditions over time such as global warming.
The description of the collection site ought
to be as specific as possible. If you
record the name of the property, it may be difficult for a botanist to
the location in 150 years if the name is no longer in common usage.
On the other hand, latitudes and longitudes
don’t change. In the past, these were
gleaned from topographic maps. Now many
collectors carry handheld GPS units.
Also, try to record physical characteristics of the site such as
textures (e.g. sandy, silty, heavy organic layer, etc.) and moisture
(dry upland, boggy area, flowing stream, lake), and the names of as
many of the
plants as possible that you find surrounding your specimen.
best to identify the plant while
fresh, but most botanists collect several specimens while in the field
transport their specimens to a common location where they can identify
press them. To keep the plant in its
best condition while you are collecting in the field, you should place
of masking tape around the stem with the collection number that
the data you’ve recorded in your field notebook and enclose the plant
large plastic bag. When you’re finished
collecting and ready to identify and press the plants, you should
one at a time from the bag(s) and place them in a plant press (see
below, although a couple of pieces of plywood and rope work just as
soon as possible after you finish the identification.
The plants should be dried as thoroughly as possible
to avoid molding and will dry more quickly if the press can be stored
in a hot
attic or a car trunk.
After completing the
information on the collection
drying the plant in a press, you will need to mount the label and the
a herbarium sheet.
A mounted specimen is
The best method for
mounting specimens is to spread a diluted museum-quality acid-free
a 16 x 24 sheet of Plexiglas (as an inexpensive alternative, try
overlapping strips of plastic wrap on a counter-top) with a paintbrush
lay the plant down in this adhesive film.
the specimen label by placing it in the glue, then
transferring it to the herbarium sheet. Traditionally,
labels are applied in the lower right corner of the herbarium sheet.
Then repeat the procedure with the plant, transferring in an
orientation so the whole specimen fits on the herbarium sheet.
Spread a sheet of
wax paper over the specimen and label and place a board on top to hold
the plant down while the glue dries. After a day or two, the
adhesive should be dry and the specimen can be stored until you’re
turn in the collection for a grade. (See the rubric
for information on how collections will be graded.)
Plant taxonomy II – making digital
the smaller collections were absorbed into larger collections at fewer
institutions, the scientific utility of the records contained in these
collections improved. Many of these
collections are now being digitized and, consequently, the data
the specimens can be made available to anyone any place in the world
internet connection. The herbarium at
the University of Connecticut has one of the most
collections of New England plants in
region and many of the specimens have been digitized.
This exercise has been designed to
familiarize you with the electronic resources that the “CONN” herbarium
has made available to you
through their online database. You may
want to conduct this exercise while your plants are drying in the press.
digital data: Pay
a “virtual visit” to the University
and generate a distribution map for one of your species.
Select “Virtual Herbarium” and conduct a “simple”
query using the genus and species name from one of your specimens. At the top of the results page, click on “Map
these results with Berkeley Mapper” to get a sense of where your
occurs. Several markers will probably
appear on the map that you’ve just created.
Click on one of these markers and follow some of the hyperlinks
what kinds of valuable data can be gleaned from this database. You can zoom in or out using the vertical
scale bar on the left side of the map but the results are often
unsatisfying. It’s better to use the
“zoom by box” (a magnifying glass icon) tool above the map. You also can toggle between the different
options (map, satellite, hybrid, terrain, etc.) in the upper right
on the hand tool and drag
the map until you can
see your own neighborhood. See if there
are any accessions of this species that have been collected near your
house. Now click back to the Virtual
link and do an “advanced” query. In the
“locality” field, type the name of your hometown. This
will bring up all of the accessions for
all species from your neighborhood for which data has been digitized. You might be surprised to find out how few
species are listed in your neighborhood.
Your specimens may be the first from your local area that will
digitized – in which case your name will appear to others who are doing
same virtual search in the future! After
playing with the features of this mapping program, answer the questions
2. Why might there
be more specimens recorded in one
location than another?
- To see just how important your
collections may become, go to the “Advanced” Query and enter the name
of your town to map accessions of all species found in your immediate
neighborhood. Zoom in on one or more of
the sites that are closest to your home. Click
on one of the markers and toggle through the accessions that have been
collected there. How many are there?
3. Locate the
accession record for Gentiana
clausa at Northwest Park in Windsor. Who
4. How many
accessions does the herbarium have from
5. From this
record it is possible to determine
that, at a minimum, this individual has collected at least
how many specimens?
6. When was the
7. Offer two
reasons why it should matter.
8. How precise is the latitude and
longitude that is recorded for this species?
9. Not all of the
locations recorded for this
species are so precise. What might account for differences in the
precision of these numbers?
10. Map the
locations of Poa pratensis. How many locations did you find?
11. If this is a common grass found in many Connecticut
lawns (it is), why isn’t it mapped in more locations?
12. Look up the
genus Celastrus. Notice that some accessions have
only a “label
name” and some have the additional field “Filed in CONN as.” What
do you think could explain these differences among accessions?
13. While you will
see records for more than one
species of Celastus, one species clearly has the
greatest number of records. Which one is
14. Try to come up
with at least one explanation for
this on your own and then look the species up online.
15. What is an
16. Go back and do
a general search of accessions
from your town. View the records for at
least five different species that were collected in your neighborhood.
When you view the individual records for some
of these accessions, you will probably see the word “introduced” under
the camera icon. This means the species is
a relative newcomer to your region (and was probably brought here by
humans – either purposely or accidentally). How many of the accessions
that you viewed from your town were “introduced?
17. What does this
mean about the condition of
natural areas in Connecticut
and does this make you concerned? Why or
18. What other
impacts may this change in the
composition of the pre-colonial ecosystem have?
19. The colonists
were not the first humans in New England and archeological evidence in other
parts of the world show humans have had big impacts on ecosystems
wherever they’ve been. Why might humans
change the landscape and what might some of these changes in the plant
communities before Europeans arrived have looked like?
20. Humans are not
the only biotic force that
changes ecosystems. Beavers can have
substantial impacts on plant communities as well. Abiotic
fluctuations such as those associated with climate can also have a
large impact. Use your favorite internet
search engine to look up “pollen stratigraphy.” What
is this and how would the information it reveals compare to the data in