Cleared leaves are modern leaves that have been bleached and
stained to make their venation patterns more visible. Leaf shape,
venation, and features of the margin, base and apex constitute
important taxonomic and physiognomic characters.
For more information on leaf terminology, download the
of Leaf Architecture. For the paleobotanist, cleared leaves aid in
identifying fossil leaf compressions.
To learn more about the use of fossil leaves in inferring paleoclimate, visit
Leaf Analysis Multivariate Program (CLAMP) Web site.
UCMP houses the Daniel I. Axelrod and the Berkeley
collections, comprising over 2000 slides of modern leaf taxa.
Leaves of the Axelrod collection are mounted in plexiglass and
are in good archival condition. However, the Berkeley
collection is mounted between glass with the mounting medium Permount
and is unfortunately deteriorating due to oxidation of this medium.
Therefore, putting the cleared leaf images online is in part a
conservation measure, with the ultimate goal of having the entire
cleared leaf collection available online and CD to serve as teaching
and research tools.
Data records for both collections are now available in the on-line
database. JPEG images are being incorporated with the specimen
records, beginning with the Axelrod collection. Some images are
also available in higher resolution "Zoom and pan" mode
(all eventually will be), which gives finer detail of the venation,
epidermis and margin areas and in many cases insect and fungal
damage, information vital for paleoecological studies.
Locality information: For leaves in the Axelrod collection,
the locality data, if any, appear directly on the slide label.
The Berkeley collection
generally has good locality information, since many of the cleared
leaves are from herbarium specimens housed at UC Berkeley's University and Jepson herbaria.
Additional information: The Berkeley cleared leaves are linked
directly to their UC Berkeley Herbarium online records using the UC Herbarium
Accession ID number. Clicking on this number will bring up all information
the herbaria have for a particular specimen, but please note that only the
herbaria’s California collection is currently web accessible.
In addition, cleared leaf specimen images are linked to the ITIS report, the USDA Plants Database, CalPhotos Database, and Google image search, providing additional images, taxonomic and geographic information for the taxon of interest.
Please note that light
and dark areas of the leaves are due to differences in stain concentration
on the actual specimen and not an effect of the image capturing
How to Search the Cleared Leaf Collection