MODULE 9: HERBARIUM PREPARATION

• HERBARIUM - a collection of plant specimen which have been preserved, labelled, and organized based on an accepted type of classification, and made available for use ni research and other scientific studies.
• Initial preparation

  • Plan what specific plant, location, date and time of collection, materials and equipment, and necessary permit to gather the specimen you chose to preserve.
  • Collecting tools
  • Field Notebook is necessary ot note al the necessary information you need about the specimen
  • Plant Press
• Plant Press

  • consist of two flat frames of wood or bamboo measuring 14in x20in
  • each frame is made up of 4wooden strips measuring 3⁄4in wide and 1⁄4in thick and another 5 strips 3⁄4 in wide and 14 in long.
  • the five short strips are spaced and nailed to the equally spaced four long strips arranged in a lattice.
• Collection of the Plant Specimen

  • Select and carefully collect healthy plant.
  • Cover the gathered specimen with newspaper and place it ni a sealable plastic bag for protection during transport.

  • for best results, the plant specimen must be pressed immediately upon collection

  • Preparation for transport

  • immerse the plants collected ni the basin containing denatured alcohol ot prevent leaves and other organs from falling off

  • put the specimens in plastic bags temporarily

  • fold hte other end of the plastic and seal ot

  prevent the dripping of alcohol
• • Final Pressing
  • Pressed specimens are opened to change the newspapers and driers and to improve the arrangement of the plant. Pressed plants must fit the fold of the newspaper and that of the plant press. If plants are too large, they must be bent into letter V, N, M or W figures.
• Drying - rapid drying is one of the secrets of retaining the green color of plant - moisture from the plant must evaporate in the shortest possible time.

  • Natural Drying - drying under the sun or in the lab under room temperature
  • Artificial Drying - drying with the use of electric burner or electric bulbs.
• Protection Against Herbarium Pests

  • Poisoning - specimen should be dipped in a poisoning solution made of 1 liter denatured alcohol, 12-15g of mercuric chloride, and 10-12ml of carbonic acid mixed thoroughly.
  • Deep-Freezing - specimens are routinely subjected to freezing temperatures for 3-4 consecutive days to kill insect eggs and larvae.
  • Fumigation - specimens and fumigants are placed in sealed chambers for several hours.
• Protection Against Herbarium Pests

  • Microwaving - use for small quantities of specimens. Drying is accompanied by irradiating at maximum power for 1-2 minutes per specimen.
  • Mounting The Specimens on The Herbarium Sheets - properly-mounted herbarium specimens must last for long periods

  The four common methods of mounting:

  • ADHESIVES - starch paste, Elmer's glue, and other kinds of colorless glue.
  • TAPES - used for strapping the specimens to the sheets.
  • THREADS - used to attach the specimen to the mounting sheet in whole or in part
  • A combination of the three methods mentioned above
• Preparation of Herbarium Labels

  Labelling

  • properly prepared label is glued to the mounting sheets
  • it is placed in the upper right-hand corner
  • a smaller herbarium label affixed on the lower right-hand corner of the mounting sheet. Make sure that the labels are attached to the right-specimens

  Accessioning

  • record of all the botanical specimens using an accession book is necessary
  • the record indicates the herbarium number, scientific name, common or local name, date of collection, name of collector and locality
• How to make an Herbarium

  • Initial preparation
  • Collection of the Plant Specimen
  • Final Pressing
  • Drying
  • Protection Against Herbarium Pests
  • Preparation of Herbarium Labels