When collecting plants for preservation and research, certain protocols and careful attention to detail are expected. There are many excellent guides available to help you, such as the ones produced by the Botanical Research Institute of Texas and the Missouri Botanical Garden. This page is a simple outline, and includes some of my own methods and tips for collecting, recording, and preserving vascular plant specimens. If you have any questions, please feel free to contact me and I’ll be happy to help you.
* In a short while I'll add a section for the collection of genetic-quality specimens, which are plant tissues used specifically for sequencing DNA. This is fairly new for herbaria, and I've developed a program at the University of Memphis Herbarium for the proper storage of this material.
To find as many different species as possible, you'll need to look in a variety of habitats. Each location you visit will have a unique community, and a collection of every species in that community should be made. Roadsides are easy to collect, and will provide a large number of common species. Forests and swamps are more difficult to collect, but they could surprise you with an interesting or rare find. I like to collect along transition areas where an open field meets the edge of a woods. In these locations you have three habitats: the open field, the shady woods, and the transition area between the two. Other good areas to look are along waterways and moist depressions, on steep hillsides, and in areas where the soil has been disturbed. Permission will need to be obtained prior to collecting on private land, or within many city or county parks. Permits are required for collecting within state and national parks/forests, or within the wildlife management areas of West Tennessee. Information about permit applications is on the RESOURCES page (forthcoming).
MAKING A COLLECTION
It’s become important to have a GPS receiver for recording the location of your collection, so get the best one you can. Don’t depend on your phone to give you readings, as they are not very accurate nor reliable.
Photography isn’t a necessity when collecting plants, but it’s so easy to get high-resolution images now there’s little reason not to take a camera. Not only will it help you remember details of the collection, it will provide record of features you may have missed and a reasonable rendition of color (which is often lost in preservation). Having a good macro setting (or lens) on the camera will be the most help, but any image is better than none. You can even use your phone if it'll give you a sharp image.
A small hand lens or loupe is handy to have in the field mostly for checking to see if a plant with tiny flowers is actually flowering. Sometimes they're close to flowering, in which case you'll want to pass on the collection of the species. The same will go for ferns and fern allies in looking at the structures that hold the spores. You might also want to examine the plant for features that may be lost or difficult to see after the preservation process, or look for tiny clues as to the plant's identification. Get a hand lens that's at least 10x, or stop by the University of Memphis herbarium and I'll give you one!
CUTTING/DIGGING TOOLSFor removing material I most often use my Felco pruners, a hori hori, and a very sturdy stainless steel dinner fork. The hori hori is a great tool for digging and prying plants from the ground, and I use the fork to tease smaller plants out of the ground without damaging the roots.
PLANT PRESSWooden presses are used to flatten the plants in preparation for mounting them onto archival paper. You can buy good quality ones from the suppliers I’ve listed in my section on pressing specimens, or make them yourself using plywood and cam-buckle straps from the hardware store. Associated with the plant press are blotters, ventilators, and newspaper (I use local news rags that are 12" x 16"), for which you'll need one of each for every specimen you collect.
OTHER EQUIPMENTI have a field press for pre-pressing delicate plants, and place sturdier plants into plastic grocery bags with some wet newspaper to keep them from wilting too much before I can get them into a wooden press. I also carry with me some small paper bags and envelopes for collecting seeds or fruits, and a measuring tape for getting dimensions. It’s also a good idea to carry some disposable gloves for handling toxic species, and antiseptic and band-aids for handling evil plants and other mishaps.
First of all—a definition: A collection is one or more specimens of the same species taken at the same time in the same place. If you cut several branches off of a shrub, that's one collection and is given one number. If you dig up a small herb, or several of that same species growing together, that is one collection and is given one number. If later on you find the same species growing down the road and collect that as well, that is a new collection and is given a new number.
All collections should be made while the plant is in its reproductive stage, either in flower, during sporulation, or (secondarily) in seed. Find a good representation of the species, not something with a deformity or one that's diseased. Collect at least three specimens of each species (= one collection). If collecting whole plants, DO NOT collect a species if you can’t leave at least several of the plants untouched—instead, list it as an associated species on the collection of a nearby plant. Also, be aware of dioecious plants where you should collect from both male and female plants if available, and monoecious plants where you will need to collect both male and female flowers from the same plant. (These species will be identified in the upcoming database.)
If a whole plant will fit on an 11″ x 17″ specimen sheet (use your newspaper sheets as a guide), then collect it roots and all. Knock off as much soil from the roots as possible before pressing—washing it off if necessary—and the remainder after the plant has dried. Collect just fertile stems from larger plants, but remember to record the dimensions of the whole plant. It’s good practice to collect extra flowers, young and mature leaves, fruit, any distinguishing parts, as well as bark from woody species. You’ll want the specimen sheet to be filled with as much material as it can comfortably handle, and the extra material will benefit researchers.
Wooden presses are used to flatten the plants in preparation for mounting onto archival paper. You can buy good quality ones from the suppliers I've listed, or make them yourself using plywood and cam-buckle straps from the hardware store. Specimens are placed into folded (printed or unprinted) newspaper, and the collector's initials and collection number are written on the outside corner of the paper. If your collection has multiple specimens, all the papers will have that collection number.
Arrange the specimen in the newspaper so important features will be visible when the plant is mounted. Think carefully because once dried, the plant will retain the form you select. Would a future researcher be able to inspect the upper and lower sides of the leaves? The inside of the flower? Are any leaf axils visible? There are countless things to consider. You also need to know how to fold, or what can be removed from, specimens that are too large for the sheet. You'll get a better idea of what I'm talking about by checking out the Missouri Botanical Garden pressing guide.
Once a specimen is in the newspaper, it's then layered in the press between a drier (blotter paper) and a ventilator (corrugated cardboard) to hasten drying of the plant. With your specimens stacked in the press, pull the straps to tighten them as much as you can. Kneel or stand on the press to really smash it down and lock it in place.
Once you have your specimens in a press they need to be dried quickly to preserve them. Herbaria have special drying cabinets that circulate heat around the presses, but you can easily build one of your own that will work just as well. I built a drier using a sink base cabinet—it uses 100-watt light bulbs as a heat source (yes, I hoarded the bulbs when they were still available) and a computer fan to circulate the air. You don't have to get fancy—I've also placed my presses in a hot car or just out in the hot sun when it was all I had. If nothing else, change the damp blotter paper every day or two. As the plants dry they'll shrink, so every few days you'll need to tighten the straps to keep the specimens as flat as possible. Drying takes 3-7 days, depending on the thickness and moisture content of the plants, as well as the humidity of the air.
DEPOSITING YOUR COLLECTIONS
Before sending your dried and labeled specimens to a herbarium you should contact the director, collections manager, or curator to let them know you would like to send them your collections. For this project, one specimen from each collection should go to the University of Tennessee Herbarium in Knoxville. This assures that official record is made in the state's inventory. Additionally, duplicate specimens should be sent to the University of Memphis Herbarium since it's a regional institution. I also send a duplicate to the Botanical Research Institute of Texas. Should you deposit more than one duplicate in a herbarium, they will exchange the extras with herbaria around the world.
PREPARING FOR SHIPMENT
Keep your specimens in the folded newspaper and place the corresponding labels inside with them. stack them neatly in collection number order and wrap them in several layers of newspaper, taping it securely closed like a package. It's not going to look "professional," but trust me, you're fine. Place your specimen pack into a shipping box, along with a short note to the herbarium saying who you are and what kind of collections you are sending (i.e. "plants from West Tennessee"). Make sure the box is filled tightly with packing material so the specimens won't move at all. Label the outside of the box: "DRIED PLANT SPECIMENS FOR SCIENTIFIC STUDY — NO COMMERCIAL VALUE — HANDLE WITH EXTREME CARE — LIBRARY RATE"
Below I've provided contact links for the herbaria I mentioned, plus Austin Peay State University, which I also recommend. If you wish to send specimens to other herbaria, you can find contact details in the Index Herbariorum.
University of Tennessee Herbarium (TENN)
Contact: Jessica Budke, Director
Austin Peay State University Herbarium (APSC)
Contact: Dwayne Estes, Curator
Botanical Research Institute of Texas (BRIT)
Contact: Tiana Rehman, Collections Manager
University of Memphis Herbarium (MEM)
Contact: Darrell Brandon, Collections Manager