Another task I’ve been undertaking in the herbarium this week is mounting plant specimens.
The museum has a lot of plant specimens that need mounting or re-mounting; some collected a long time ago and some recently collected. If you’d like to learn more about how the museum continues collecting; based upon more of a thematic cross-discipline exercise rather than just ‘filling in gaps’, then check out our new collecting project on the theme of trees.
However, the majority of the plant specimens currently waiting to be mounted were collected long ago. For example, lots of the alpine plants that I’ve been mounting this week were collected in 1836; about the time Charles Darwin was returning home on the Beagle! They need mounting for a number of different reasons; they may have been initially mounted and the old herbarium sheet has become unsuitable; or they may never have been mounted in the first place. Some of the specimens have been kept in old papers from the day (an interesting read!); some in between unwanted diary sheets or book pages; and one was even kept in between a piece of marked French homework (a lot better than mine ever was!)
At Manchester, we have decided that the best way of mounting these specimens is by using straps. These are small strips of gummed-linen. Done well, this is a competent form of attachment that can allow for expansion and will hopefully keep the plant secure for a long time. It is also easily reversed if needed. This is in contrast to the method of gluing the specimens themselves using PVA, as described in my previous blog post.
The herbarium specimens I was working on aren’t going to be used for display purposes so it doesn’t have to look perfect. Securely mounting the specimen on good quality acid-free paper is the most important thing; that is why I may have used a few too many straps or straps that were too thick in places. It is important to mount plants to one side of the sheet or the other if you can; to avoid the sheets bowing in the middle once they have been laid away. I find it best to start applying the straps at the bottom of the specimen first.
The herbarium sheet label (and extracted information) is glued using PVA to the bottom right corner of the sheet and the university stamp is applied so that we know where the material belongs if it is subsequently loaned out.
A packet or capsule can be made for loose plant material or sections that are too small to mount.