I. A Plant Morgue
    An herbarium is a collection of pressed, dried, and labeled plants (and may also include other types of collections including wood or seeds). Perhaps a less morbid analogy is that an herbarium is a reference library of plants. It is generally agreed that Luca Ghini (1490-1556), Professor of Botany at the University of Bologna, prepared the first herbarium specimens as we recognize them today. His students, Cibo, Turner, Aldrovandi and Cesalpino also made herbaria, some of which still exist (John McNeill, 1997; Taxacom Discussion). Another contender for the oldest herbarium specimen is an olive branch removed from King Tut’s tomb (Craig Hilton-Taylor, 1997; Taxacom discussion).

II. Value of Herbarium Specimens

1. Monetary Value. Herbarium specimens can be considered priceless (since they are irreplaceable) or nearly worthless ("if you've seen one redwood you've seen 'em all" - R. Reagan). Various groups have calculated the approximate value of herbarium specimens. These calculations are typically based on the value of the collector’s time, the value of the curator and staff time, the cost of electricity, paper, glue and other supplies and other costs inherent in storing the collection. These calculations typically result in values that range from $3 - 6.00 per specimen (Sue Thompson, Carnegie Museum) to $10 (American Systematics Collections) to $52.50 (see Armstrong, 1992). Whatever the figure, none take into account the intrinsic scientific value of the specimen.
    
2. Scientific Value. The information content of a herbarium is tremendous. Herbarium specimens document: (a) the appearance of a plant in a particular locality at a particular time of year; (b) the range of variation within a species; (c) the nature of evolutionary processes; and (d) when a particular plant flowers or fruits (phenology). They also (e) provide material for study away from the field or at another season. And, they serve as: (f) vouchers, or voucher specimens, that document the identity of plants used in taxonomic, chemical (i.e., DNA), or cytological (i.e., chromosome counts), or other studies, and as and (g) type specimens - specimens upon which names are based. Finally, (h) herbarium specimens may have a wealth of information about the medicinal or food or utility of the plant (Siri von Reis Altschul, 1977).

III. Herbaria around the world
    The number of specimens in different herbaria varies from just a few to millions. The CSB/SJU Biology Department herbarium has approximately 28,000 specimens (an estimate - you are welcome to count yourself - one bonus point for an accurate count). Large herbaria include (# specimens in parentheses): Museum of Natural History, Paris (8.8 million); Royal Botanical Gardens, Kew (7 million); Komarov Botanical Institute, Leningrad (5+ million); NY Botanical Garden (5.3 million); Harvard (combined herbaria, 4.8 million); US National Herbarium (4.4 million), Smithsonian (4.1 million); Field Museum of Chicago (2.4 million) (data from Index Herbariorum). The University of Minnesota has over 800,000 specimens.

    Index Herbariorum lists the world’s herbaria, size, types of collections and a wealth of other information. This excellent resource is now on-line (see references). Each herbarium is given a standard acronym. CSB is the acronym for our herbarium.  Index Herbariorum is now available on-line.

IV. Specimen Arrangement in the herbarium
    Specimens are typically filed by family in a phylogenetic sequence based on a classification system. The Engler- Prantl system is commonly used in many North American herbaria. Cronquist's system is popular with more recently-arranged herbaria. Within a family, genera are alphabetical, and ditto for species in a genus. Specimens may be sorted by geographic region within these categories. Dalla Torre and Harms provided numbers for each family and genus based on the Engler Prantl system (see Jones and Luchsinger).  In contrast, a few herbaria file collections alphabetically, again by family.

    There are advantages and disadvantages to each method: 

• Down With Alphabetical Herbaria
• Up With Alphabetical Herbaria

What do you think?

V. How to find specimens in the herbarium
    This depends upon how the herbarium is arranged. We will discuss finding specimens in our herbarium, which is arranged by Cronquist's system (1991).

VI. Handling herbarium specimens
    When handling herbarium specimens you must do it very carefully because they are very FRAGILE and VALUABLE!   When handling:

• use two hands;
• don't twist or turn upside down;
• don't page through them like a book;
• don't bend, twist, fold, spindle or mutilate;
• place any material that falls off in a packet attached to specimen;
• re-file in the correct spot - this is very critical. When in doubt leave it for the herbarium staff;
• if a specimen is damaged, bring it to the attention of the herbarium staff.

    Some Do's and Don't for handling specimens follows:

VII. Annotating herbarium specimens
     If a specimen is misidentified, a small annotation label is usually affixed to the specimen indicating your opinion of the correct name, your name and the date.

VIII. Pest Control
     (a) freezing (common technique used in many herbaria); (b) repellents (like para-dichlorobenzene); (c) fumigants; (d) microwave.

IX. Loans and Exchanges - discussed in class

X. Studying Herbarium Specimens
    Material should not be removed from a specimen without the permission of the herbarium curator. When studying specimens, first use material in any packets that accompany the specimens. Only small fragments should be used. Return unused material to the packet with the specimen.

    To rehydrate and soften a dry specimen, apply 10% glycerin in water or boil the specimen in water to which is added a few drops of detergent or simply add a few drops of warm soapy water. Most identifications by professional botanists are done on dried herbarium specimens. However, it is easier to study fresh specimens if they are available. If possible, save some fresh material to do your identifications.

    After identification is complete, place any unused/leftover material in the specimen packet.

XI. Web sites:

• Field Techniques Used by Missouri Botanical Garden. by R. Liesner.  This is an excellent site.
• Guide to Collecting Vascular Plant Specimens for Museum Specimens.  by Anita Cholewa (U MN)
• Index Herbariorum; NYBG Website
• Synonymized checklist of the vascular flora of the US, Puerto Rico and the Virgin Islands
• Tarozzi, Andrea (1996) A Herbarium. online introduction for children (& adults)

XII. References:

• Armstrong, J.A. 1992. The funding base for Australian biological collections. Austral. Biol. 5: 80-87.
• Burger, WC 2004.  Another Opinion: Up with Alphabetically Arranged Herbaria (And with Floristic listings too for that matter).  Plant Science Bulletin 50 (1): 7 (Spring)
• Funk, V  (2003)  Down with Alphabetically Arranged Herbaria (And with Floristic listings too for that matter).  Plant Science Bulletin 49 (4): 131 (Winter).
• Holmgren, P., Keuken, Schofield. 1990. Index Herbariorum. New York Botanical Garden, Bronx, NY.
• Monastersky, Richard. 1995. For the sake of Sue. What will happen to the world’s best T. rex? Science News 148:316-317.
• Pedersen, B.B. 1987. An Herbarium for Seawell. Carolina Tips 50: 5-7.
• von Reis Altschul, Siri. 1977. Exploring the herbarium. Scientific American. pp. 96 - 104.