Yesterday I spent the day at a workshop run by the Natural Sciences Collections Association called “Caring for Botanical Collections.” This one day workshop took place at Liverpool World Museum and involved both theory and practical workshops run by Curator of Botany Donna Young, Botanical Conservation and Research Officer Vicky Purewal from National Museums Wales, and Janet Ashdown, senior conservator at the Linnean Society.
The morning started off with tea and a talk about what a Herbarium is. Though Herbaria usually mostly consist of dried, pressed plant specimens mounted on sheets, they can also include large collections of the following items:
-Freeze dried specimens such as Fungi
-Packeted Bryophyte specimens
-Slides and photographic plates
-3D plant models
We also went over basic Herbarium maintenance, which includes pest control, humidity control, how to handle specimens and collections arrangement.
Janet Ashdown gave us a talk on the collections at the Linnean Society. The collections there are stored in their original packaging, which is unusual, but they are kept that way as an example of a historic herbarium. You can read a bit more about that here.
After lunch we were given practical demonstrations in paper conservation and mounting specimens.
First Janet showed us how to repair a tear in damaged herbarium paper using Japanese tissue paper. The paper was attached to the damaged area by gently brushing on methyl cellulose. Japanese tissue paper is pretty strong stuff, and can be used for a variety of natural history repairs, not just botanical sheets. I have used it to repair bird legs on damaged taxidermy.
Janet brushing the methyl cellulose onto the sheet:
Next Donna showed us how to mount a plant specimen onto a herbarium sheet. The two most common methods used in Herbaria are use of PVA adhesive or gummed linen strips. As a personal preference I prefer the gummed linen strips, as they are reversable should the specimen need to be remounted in the future.
Vicky Purewal showed us how to spot contaminated specimens by using a UV light. Historic specimens were often treated with mercuric chloride in the past to keep insects pests off. Obviously we now know mercury is a highly poisonous substance, so precautions such as wearing gloves should be taken when handling contaminated specimens.
In the image below, you can see a bright orange spot on the dried plant specimen. This is a a spot of highly concentrated mercury!
Next we were given the opportunity to work on mounting a herbarium specimen of our own. Everyone got given a fresh specimen wrapped in newspaper, gummed linen strips, PVA adhesive, specimen capsule envelopes, water, a brush and a label.
I was given a plant called a Serbian bell flower, which is a popular perennial in gardens. The petals can even be eaten and used in salads, though I don’t recommend you try eating anything off a herbarium sheet!
As the final part of the day, we were given a tour of the Liverpool World Museum Herbarium. Below is a photo of a type specimen and its corresponding illustration, which was one of my favorite things we were shown in the Herbarium.
All in all, it was an enjoyable and highly useful day. Thank you, Donna, Vicky,Janet and Wendy!