The Botany Department houses about 1.4 million specimens spanning more than 300 years of history. Specimens such as these are foundational to botanical research; they provide scientists insights into many fields of study, such as evolution, ecology and climate change. In this post, we’ll teach you how to make your own botanical specimen at home.
Collect Your Plants
The first step to making a botanical specimen is to collect your plant. When picking a plant, aim to collect as many interesting features as possible. These can include flowers, fruits, leaves and roots. If you are collecting a small plant, you may want to dig it up whole, but if you are collecting from a tree, you probably only want a branch. Always be sure to collect at home or ask the land owner for permission.
Along with your plant, you should gather information. Things to record include: collector (that’s you!); date; plant identification; country, state and county; locality (e.g. “the corner of Wood St. & Vine St. next to the library”); habitat (e.g. “swampy marsh”); description (e.g. color, smell, etc.); habit (e.g. vine, tree, shrub, herb); height; and if the plant is cultivated or wild. All this information will go on the specimen label.
Press Your Plant
Once you’ve collected your plant, it’s time to preserve it. To press your plant, put your newly collected specimen between two sheets of newspaper. Parchment paper can also work in a pinch. Before pressing, spread the plant into the position you want it to dry in. Keep in mind that you that you want all the plant’s interesting features to be visible. If the leaves are all facing the same direction, flip one leaf over to reveal the underside — there may be interesting features, like hairs, on the bottom side that do not appear on the top.
When you’re happy with how your plant is positioned, add weight to hold it in place. You can do this with a professional plant press, or at home, a stack of books works just as well. Then, leave your plant for a week. When you come back, it should be flat and dry. While you’re waiting, it’s a good time to type up all the information you recorded and print out a label for your specimen.
Gather Your Materials
The first step in mounting your specimen is to gather your materials. You’ll need a piece of paper on which to mount your specimen, glue (school glue works well for home projects), a paintbrush, and a damp sponge. If you are looking to create an archival quality specimen for a formal collection, you’ll want to get acid-free, 100% rag, standard size herbarium paper as well as herbarium glue. You can buy these supplies through University Products.
A needle, thread, pushpin and linen strips are optional, but can be useful for mounting more bulky plants. A small folded paper packet for holding plant fragments is also optional. Finally, you’ll need your pressed plant and specimen label.
Lay Out Your Specimen
Next, you want to lay your specimen out on the paper to make sure everything fits. The label you made goes in the bottom right corner. Try to leave empty space over the label as this is where annotation labels will go if the specimen gets reidentified. You generally want to put roots toward the bottom of the paper and flowers towards the top. You’ll also have to pick which side of your specimen you want facing up to allow you to see the most interesting features. If you’re including a fragment packet, arrange that on the paper as well. When you’re happy with how everything looks, you’re ready to glue.
Glue Your Specimen
First, apply glue to the back of your label. Use a paint brush to evenly apply a thin coat, making sure to get the edges. Then, smooth the label onto the spot where you arranged it. If you’re using a fragment packet, glue it to the paper in a similar way. Next, pick up your plant specimen and flip it over. Use your paintbrush to dab glue on to the specimen until the entire back side is dappled, including stems and the bases of flowers and fruits. Next, arrange your specimen over your paper and gently guide it down. If any stray glue gets on the paper, you can gently dab it away with your damp sponge.
Let the Glue Cure
After you’ve glued your specimen it’s time to let it dry. Put wax or parchment paper on top of your newly glued specimen and then add weights. This will help your specimen dry flat. Leave your specimen to dry for at least 24 hours.
Some Additional, but Optional, Finishing Steps
Take your plant out from under the weights and behold your hard work! If everything seems secure, your specimen is finished. If you want to add a little bit more reinforcement, you can sew your plant down or add linen strips.
To sew, identify some three-dimensional spots on your plant such as thick stems, bulbs and fruits. Use your pushpin to gently poke holes on either side of these structures. Then, thread a needle with some neutral-colored thread and flip your specimen over. Beginning from the back, pull your needle through one of the holes you made, over your plant structure, and then back through the hole on the other side. Tie the two ends of your thread together on the back side of the specimen.
Linen strips are a special material with adhesive on one side. They are particularly good at securing smaller, flatter structures such as temperamental pine needles. Once you decide where the linen strip will go, cut it down to size; they can be as thin as 1 mm and should overhang the plant structure by 1 cm on each side. Then, wet the adhesive with your damp sponge and smooth the linen strip over the plant structure. Squares of linen strip can also be smoothed over any knots on the back of the specimen left over from sewing.
Fragment packets are folded packets which contain any little bits of plant material that may fall off a specimen across the decades. To make a fragment packet, cut a paper rectangle to roughly 4 by 5 inches. Fold the paper into thirds the long way with the top third being a little smaller than the other two. Fold the bottom third up and the top third down. Next fold it into thirds the narrow way, with the two thirds on the sides being slightly shorter than the third in the middle. Fold both of these flaps over your other folds and tuck one onto the other. You now have a folded fragment packet. If you want to be fancy, you can cut the side flaps into triangles.
That’s it; you’ve finished! Display your specimen or store it in a dim dry place and begin your own botanical collection.
Written by Emily Humphreys, Eli Kirk Price Plant Science Fellow interning in the Botany Department at the Academy of Natural Sciences