Digitized pictures of herbarium sheets

[Guido at]

Forwarded from the Peperomia discussion group 
(http://www.egroups.com/group/peperomia)


I'd like to draw your attention to the Dutch Herbarium Type Specimen (DHTS)
database as an example of how a database nowadays should provide not only
data but digitized pictures of the herbarium sheets too. For some
fundamental research, physical examination of the herbarium specimen (and
even sampling) is unavoidable but as handling and shipping of specimens is
often in contradiction with the needs of permanent conservation,
manipulation should be kept to a minimum. For a lot of determination work
good digitized pictures could be very useful and diminish drastically the
need of sheet handling. In addition, with quick Internet access & search
possibilities, the use of such pictures could substantially shorten the
determination time. The DHTS database provides pictures of 70 Peperomia
specimen sheets
(http://nhncml.leidenuniv.nl/scripts/oopwebv24.dll?ent=1&rec=300017&sct=1&ge
Name=peperomia&first=300015) in a resolution of  1018 x 1530 pixels,  which
is the same resolution as images provided by the NY herbarium. Although NY
already publicly announced their digitizing program
(http://www.nybg.org/bsci/herbarium_imaging) only one Peperomia sheet has
been linked until now (the holotype of Peperomia gracieana Görts. An image
of an isotype may be found in the DHTS database). You may find a few other
examples (of  Peperomia hammelii Grayum and Peperomia trichomanoides Grayum
) distributed by the INB herbarium but they 're only provided in a
resolution of about 560 x 600, obviously to low.
Digitized images, on the other hand, do not upgrade the, sometimes poor,
state of herbarium specimens and the recent initiatives to link to images of
living plants (e.g. search for Peperomia herzogii at MO:
http://mobot.mobot.org/Pick/Search/pick.html) are to be encouraged.

Guido Mathieu
Botanical Garden State University Ghent (Belgium)