Hidden away at the Crosby Arboretum, a secret garden lies in two metal file cabinets. Over 2,000 pressed plant specimens have been mounted and meticulously arranged by plant family, comprising the Arboretum’s herbarium.

Have you ever plucked a flower or plant as a souvenir during a nature walk, and pressed it into the pages of a nearby book? Coming across such a specimen years later, I’ve often marveled at how well their color has been preserved. The antiquarian book collection that we enjoyed unpacking recently had a few of these gems included between the pages, which has made them even more special.

Imagine a cabinet, room, or even an entire building devoted to the practice of preserving plant material. Imagine also, the hot summer days spent searching for the specimens, and the many mud puddles and chiggers endured by the collectors.   

In a herbarium, such as the Crosby Arboretum’s secret garden, one will find preserved and pressed plant specimens arranged by plant family, genus, and species. Specimens are glued, sewn or taped to a heavy sheet of high-quality paper with a label telling where it was found, the date collected, and the name of the person who collected it. The specimens are kept in special storage cabinets along with chemical preservatives.    

There are several thousand herbaria (the plural of herbarium) in the world, of all sizes. The largest herbarium in the world is in Paris, and was founded in 1635. It has around nine million specimens, some which are hundreds of years old. Collections can last for a long time if they are kept under the right conditions so the specimens. Some plants in herbaria (the plural of herbarium) are now extinct.

The specimens at the Crosby Arboretum are the collection of Dr. Sidney McDaniel, a botanist from Mississippi State University. In the early 1980’s, Dr. McDaniel performed detailed plant inventories of the Arboretum’s associated natural areas. Each specimen is marked with the Crosby Arboretum stamp, and given an accession number.

Many of our specimens were organized by a local volunteer, Gordon Ousset, along with former Senior Curator, Melinda Lyman. In August 2010, the Arboretum was pleased to receive a donation of several hundred additional specimens from the collection of  Hattiesburg biologist, Dr. Richard Moore. The Arboretum’s future education building is planned to contain a separate herbarium room that will house the collection.  

Botanists and taxonomists are among the researchers who will study herbarium specimens, for example, to determine how certain species have changed over time. Just like books, herbarium specimens are loaned out between institutions to help researchers who are working on certain groups of plants. They can be used by colleges and universities if live plant material is not available for teaching purposes.

You can name any plant and it seems to be found in the Arboretum’s herbarium collection. The collection contains unusual species such as LeConte’s thistle, Alabama croton, chinkapin, and nine species of orchids. There are numerous species of the yellow-flowered St. John’s wort (Hypericum), many kinds of hickories and oaks, several types of deciduous magnolia, and even four specimens of Chinese privet (Ligustrum sinense), along with a sheet of Chinese tallow tree.

What fun it is to turn through these sheets. Some of my favorites are those which remind me of walks in the Smoky Mountains, such as bloodroot and trillium. There are twelve species of hawthorn (Crataegus), including parsley hawthorn and mayhaw (which is also called riverflat hawthorn), and horse sugar (Symplocos tinctoria). Carnivorous plants are also represented, such as spoonleaf sundew (Drossera intermedia), pink sundew (Drossera capillaris), the yellow pitcher plant (Sarracenia alata) which is seen throughout the Arboretum, hooded pitcher plant (Sarracenia minor), and parrot pitcher plant (Sarracenia psittacina).

With only a few common materials, you can build a simple plant press that you can carry with you on a nature walk, and use to preserve flowers and other plant material. Search the Internet to find detailed instructions for making a plant press. Dried plants may be used for craft projects, such as card making, or added to the pages of your nature journal along with a note or two. They may be arranged in a “bouquet” and sandwiched between two glass panes, held together with soldered metal foil frame. Again, the steps for such projects can be located on craft websites.

I once remember hearing that Martha Stewart favored using her old phone books to press flowers for her projects. Especially easy to carry on a field trip are those half-size versions you may have seen – the ones that are way too small to read without a magnifying glass. Seems like flower pressing would be a much more reasonable use!

Why not create your own mock specimens? Use a high-quality, heavy paper on which to mount your plant material, and add its Latin name, where it was collected, etc. and mount in a frame. Finally, remember to be respectful when collecting your plant materials. Do not collect a plant if it appears to be uncommon and the only example in an area. Obviously if you encounter a field that is full of the same species, you can be assured you will not be decimating a population if you collect a specimen. And get permission prior to collecting on a property that is not your own.  

If you are interested in seeing the Arboretum’s herbarium, please call ahead at 601-799-2311 to make arrangements for your visit.

 For more information on the Arboretum’s events and programs, please visit www.crosbyarboretum.msstate.edu or the Arboretum’s Facebook page. The site is open Wednesday through Sunday from 9:00 a.m. to 5:00 p.m., and is located in Picayune, off I-59 Exit 4, at 370 Ridge Road (south of Wal-Mart and adjacent to I-59.)

FOR FURTHER EXPLORATION:  

Search the Internet to read more about herbaria in the United States. Research the story about the species Thismia americana, an extinct plant that occurred in wet prairies in the Chicago area.