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    Destructive Sampling of Specimens

Two important missions of herbaria are: 1) to preserve the botanical specimens entrusted to their keeping; and 2) to make the specimens available for study by researchers. By and large, the primary uses of herbarium specimens, such as examining morphology or recording distributional data, are non-destructive. Destructive uses of herbarium specimens (such as anatomical preparations or removal of pieces for DNA extraction) are generally strongly discouraged.

The University and Jepson Herbaria nevertheless acknowledge that there are instances in which the removal of a limited amount of material for destructive sampling does not seriously compromise the value of the specimen for other purposes; if done properly, the value of the specimen may even be enhanced in that it has acquired additional status as a voucher. Our policy on destructive sampling is therefore as follows:

  1. Herbarium specimens should not be the source of first choice if there are other available sources for the desired material (e.g., field collections, botanical gardens). Collaboration with local collectors, for example, can be a mutually satisfactory arrangement.
  2. Destructive sampling will continue to be considered the exception to the rule, not the normal procedure. As such, permission to remove material must be requested in writing in advance and is subject to specimen by specimen approval.
  3. Material may be removed only from specimens that have an abundance of the kind of material being removed, such that the value of the specimen for non-destructive research is retained.
  4. Destructive sampling of type specimens or similarly valuable historical specimens is not permitted unless: a) the information to be obtained is of critical significance; b) there is absolutely no other way to obtain the desired material; c) sufficient material exists; and d) a special exemption is granted.
  5. Specimens from which material has been removed are to be annotated to indicate what was removed, when, where, and by whom. In light of the status of the specimen as a voucher, a reference to where the results are published and/or material is deposited is highly desirable. Example:
    Leaf material removed for cp-DNA sequencing at UC by A.K. Johnson on 25 March 1996, in conjunction with doctoral studies on the phylogeny of Rosidae. GENBANK #1237; unused cp-DNA banked at UC; results published in Amer. J. Bot. 86:122-154,1999.
Thank you for your cooperation with this policy. Please contact us before proceeding with any destructive sampling that has not been approved in writing.