School of Sciences, Lautoka Campus BIO509 Botany Lecture 37: Herbaria and Plant preservation

Herbaria Libraries of dried, pressed (and/or liquid-preserved) plants, algae, and fungi, arranged and labeled so that specific specimens can easily be retrieved. Some have millions of specimens. Specimens are stored in airtight cabinets. Collections must be kept bug free.

Methods of Preparing Herbarium Specimens Materials for pressing: Hardwood plant press. Strong straps (2). Cardboards (or aluminum corrugates). Old newspapers. Blotters.

A representative sample (with stem and leaves, flowers and fruits) is selected to fit on the newspaper. The specimen is put into the newspaper, arranged to show both leaf surfaces. If the plant is too big, use a representative sample.

One specimen per newspaper, one number per species. A field number (your own numbering system) is written in pencil on the outside of the page. Keep notes in a field book about location, habit, color of fruit or flower, habitat, date and the specific number. It is helpful to keep specimen records in a record book.

Cardboards and blotters are added. The press is tightened to compress the specimens. The press is put into a drier (the sun does not work in the tropics). The press is checked daily and tightened as needed. Drying may take one to several days.

Use herbarium paper, which has a high rag content, for long life. The paper should be 29 x 42 cm. Water soluble glue is usual, but some people use plastic glue.

Put specimen into glue on a glass and transfer it to the paper. Or, put specimen on the paper and strap down with gummed strips or globs of blue, with weights to hold it in place until it is dry.

Leave the bottom right hand corner free with enough space to put a label approximately 8 x 13 cm in size. Add a label, with typed information, including family, scientific name, location, date, collector, and date.

Storage of Herbarium Specimens. Specimen is then best put into a plain newsprint folder. These are stored in manila folders, arranged in alphabetical order in the genus, in the family. The families are put into alphabetical or taxonomic order.

Questions??