Handling and Sorting
buckets, trays, bowls
glass bottles and vials
permanent ink pen
labels or waterproof paper
If samples are to be sent off for identification and processing, prepare specimens for transport per instructions of receiving laboratory. If preparing specimens for pressing, if fixed
remove from fixative and rinse in tap water. Remove any sand or debris that is not part of the
specimen. Separate samples into workable groups that may be grouped on herbarium sheets,
such as large and small specimens, samples from same habitat, or taxonomic groups (greens,
reds, browns), etc. Carefully track samples with labels and notes for proper records.
Pressing Algal Specimens
plant press or two boards and weights
drying blotters or newspapers
tweezers and small paint brushes
tray or cookie sheet larger than herbarium paper
To facilitate sample tracking, use a
numbering system where each specimen has an unique number. Note specimen
information on lower right hand corner of the herbarium sheet before pressing
specimen. If specimens are only for private vouchers, more than one sample may
be put on an herbarium sheet to save on materials. Museum herbaria require one
specimen per sheet.
Larger, coarser specimens may be laid
directly on an herbarium sheet on a flat surface. Spread out branches and
holdfast/rhizoids in one plane with tweezers or wet paintbrush. If the holdfast
is too thick, remove a portion to ease pressing. For more delicate specimens,
place the herbarium sheet on top of a piece of plastic, cloth, grid, etc. the
size of the herbarium paper and submerge in a tray 75% filled with water.
Floating the specimen in the water, arrange specimen over the herbarium sheet
with brushes and tweezers. Slowly raise the base piece with the herbarium sheet
and specimen out of the tray and allow to drain.
Place herbarium sheet and specimen on dry
blotter or newspaper that lies on a cardboard ventilator and cover specimen with
sheet of wax paper. Place another blotter layer over the wax paper, top with
another cardboard ventilator, and put in plant press. Continue adding specimens
to the plant press so that each specimen is covered with wax paper between a
layer of blotters, enclosed by a layer of ventilators. Firmly tighten the straps
of the plant press. 12-18 hours later replace wax paper and blotters or
newspaper (all materials can be dried and reused indefinitely). Reexamine after
24 hours and again replace blotters if needed. Place in dry, well ventilated
area. Depending on thickness and water content, specimens may dry in 1 to 10
days. Remove and store herbarium specimens in well ventilated area (Smithsonian
Website; Tsuda & Abbott, 1985).
Herbarium Pressing Exceptions
Gooey slippery specimens, such as certain
Predaea, Trichogloeopsis, Liagora, Acrosymphyton, Dudresnaya, etc.
are harder to handle. Position plant on dry herbarium sheet using brushes, water
and tweezers, place herbarium sheet on flat surface, and let air dry. Do not
cover with wax paper or layer.
Small turfs and epiphytes require slide
mounting, which is not covered in this manual.
Carolina Biological Supply Company
2700 York Road
Burlington, NC 27215-3398
15702 119th NE
Bothell, WA 98011
Abbott, Isabella A. and George J. Hollenberg.
Marine Algae of California. Stanford University Press, Stanford,
Abbott, Isabella A. 1999. Marine Algae
of the Hawaiian Islands. Bishop Museum Press, Honolulu, Hawaii.
Tsuda, Roy T. and Isabella A. Abbott. 1985.
Collection, handling, preservation and logistics, pp. 67-68. In:
Littler, M.M. and Littler, D.S. (eds.),
Ecological Field Methods: Macroalgae. Handbook of Phycological Methods.
Cambridge Univ. Press, New York.
Smithsonian Institution, National Museum of
Natural History, Department of Systematic Biology:
Cryptogamic Botany Company: