Policy on Destructive Sampling of Herbarium Specimens The University of Washington Herbarium both preserves botanical specimens and makes them available for study. Most uses of specimens, such as examining plant morphology or recording locality data, preserve the specimen for future use. Some uses, such as anatomical preparations or removal of tissue for DNA extraction, are destructive to the specimen. Destructive uses are strongly discouraged. However, the removal of a small amount of material often does not compromise the worth of the specimen, and may actually enhance it when the specimen becomes a voucher for research.
Herbarium specimens should not be considered the first source of material. Other sources include botanical gardens, horticultural suppliers, and field collections. With advance notice, many herbaria and native plant societies can find local collectors to assist with field collections. Destructive sampling is the exception, not the norm. Permission to remove material must be requested in writing, in advance. It is subject to specimen by specimen approval. It may be requested that staff at the University of Washington supply materials from specimens. This is subject to the usual criteria. Photocopies of labels and specimens may be supplied, but this is also done at the discretion of the staff. Only specimens with abundant material of the tissue to be sampled may be used. Type specimens or other historically significant specimens may not be used for destructive sampling unless: