How to Make a Herbarium

Herbarium Technique

Making a herbarium is exciting and rewarding, as each plant you press provides you with a valuable experience, allowing you to connect more closely with the plant through observing and working with it, and helping you to understand and remember it in a way that is never possible from just reading about it in a book. It consists of a three part process – collecting the plant material, pressing & drying, and mounting. Here are my recommendations learned via experience and years advising students and receiving their helpful feedback.

Niki Lawrence

COLLECTING

Materials list for plant collecting: –

• Plant press
• Plastic bags
• Garden secateurs & trowel
• Small note book & pencil
• Jeweller’s tags (optional)
• Camera (optional)
• GPS & altimeter (optional)

Plants chosen should be good representatives of the species and should contain all the essential features necessary for identification, i.e. leaves, stems, flowers & seeds (+ roots if suitably small and the plant is common and abundant).

Collecting too many plant specimens during field trips is wasteful; it is recommended that you collect only about three samples of your chosen species to ensure you have adequate space in the plant press and sufficient time and attention to devote to each specimen. Taking 4 – 10 specimens is standard practice for official herbarium collectors as usually one specimen is given as a courtesy to the nearest herbarium in the region or country of origin and another is lodged with the main official herbarium in your own country (e.g. Kew Gardens Herbarium), and another might be sent to a specialist to view.

Sexuality: Remember to check if your plant is bisexual, or if it is monoecious (sex organs on different flowers but on the same plant), or dioecious (plants contain either male or female flower but not both). For example, Urtica dioica (Nettle) is dioecious so you will need examples of both male and female plants in order to represent the species clearly.

If very small plants are being collected then gather enough so that several small specimens can sufficiently fill three A3 mounting sheets – mounting one tiny specimen on a big sheet looks odd.

Preferably collect specimens in dry conditions, a good time being mid-morning, after the dew has dried but before the heat of the day causes plants to wilt. If specimens are at all wet or you need to wash soil off the roots then dry them carefully before pressing.

Field notes must be recorded at the time of collection, noting the following:

Date, collection number, location, habitat, habit, special characteristics.

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