National Herbarium of Trinidad and Tobago

The herbarium collections of plant material are the working stock for the taxonomists and other scientists who can make use of them. They are also the repository of basic botanical knowledge for the country of Trinidad and Tobago.

Clearly they need careful curation and maintenance, and this is one of the main jobs of the herbarium staff.

The main collections are of dried, vascular plants, mounted on thick-grade archival paper and placed in species folders within genera, and arranged by plant family within vacuum-sealed metal cabinets. The room temperature is maintained at 23oC to prevent the deterioration of the plant material by pests and diseases.

There are subsidiary collections of lower plants - fungi and algae, also kept in similar conditions. Small collections of wood, seeds, and fruit are also maintained by the herbarium.                                                                                                                                                                                                                                                                                                                                  

The method of storage must allow for almost indefinite storage of the specimens, some of which are more than 150 years old. Dried plant material is very delicate, and so must be handled with great care, and as seldom as possible.

The damage caused by fungi and bacteria is actually less important than that done by insects, so it is important to disinfest the new plant material before it is mounted on the herbarium sheets and placed in the main collection.

It is also necessary to continually protect the main collection from the build-up of insect populations in the cabinets. This is done on a continuous basis by placing the herbarium folders in an industrial freezer at -30oC for at least two hours and then replacing them on the shelves. The entire collection is fumigated biennially using the recommended fumigant 'Vikane©'.