Diatom Herbarium Policies

Diatom Herbarium Policies

The ANSP Diatom Herbarium is a unit within the Center for Systematic Biology and Evolution. The mission of the Herbarium is to support diatom research. The staff of the Herbarium includes Dr. Marina Potapova (Curator) and Ms. Laura Aycock (Collection Manager). The Herbarium is governed by the general ANSP Collection Policy; the following document outlines procedures specific to the Diatom Herbarium.

Collection Use Policy


The Herbarium is open Monday to Friday by appointment. The ANSP staff and visitors are encouraged to use the Herbarium with the permission of the Curator or Collection Manager. Arrangements to visit must be made in advance with the Curator. Visitors should sign the guest log and include their name(s), date of visit, research project, materials examined, and institutional affiliation. Small grants for travel and living expenses are available on a competitive basis through the Jessup-McHenry Fund Committee.

Material Handling


Slides have to be removed from the boxes or trays carefully. A note should be placed in the slot indicating when and by whom a slide is removed. A light microscope equipped with a digital camera is available for visitors to examine the slides.

Processed and Unprocessed Samples

Secure permission and a signed loan form from the Curator or Collection Manager before removing any material from samples. Notify Herbarium staff about broken vials, lids, or torn packages.

The Library

The Diatom Herbarium library consists of books catalogued in the ANSP Library, the diatom reprint collection, and the personal library and reprint collection of the late Dr. C.W. Reimer (loaned to the Curator). Visitors are welcome to use literature in the Herbarium area and may request materials housed in the main stacks from the Collection Manager. At the end of each day all reading materials should be returned to their places or to the Collection Manager and may never be removed from the Herbarium area. Facilities for scanning Herbarium literature are available upon request.

Index Card Files

The following index card files may be useful to find materials of interest: the geographic location files (one for slides and another for raw and processed samples), the bibliography file, the American distribution file, the taxon file, which includes a catalog of slides where taxa have been identified, and the new species file, which includes scanned illustrations and descriptions of  taxa described or transferred after 1932. Please replace cards immediately after use and report any damaged cards to the Collection Manager. 


The Herbarium database provides an inventory of cataloged slides and materials. Please consult the Herbarium staff for more advanced queries of Herbarium holdings.


We appreciate annotations, which are notes that update the determinations and/or cite the project for which specimens were examined. Annotations may be either handwritten or submitted electronically. See the Curator for more detailed instructions on format. Please do not write directly on any herbarium materials.


No specimens may be removed from the herbarium collection without proper loan authorization and forms. 
All loans to individuals are made through the affiliated Institution of that individual and are considered loans to that Institution. The borrowing Institution has the responsibility for the secure custody and proper return of the specimens. Specimens may not be removed from the institution to which they were loaned without prior permission and appropriate paperwork. Loans are made without charge or service fee; it is expected that the borrowing institution will pay the costs of return shipment. 

Loan requests may be sent to the Curator via email or ordinary mail. Requests should include:

  • The name(s) of the researcher(s)and their affiliated research institution(s)
  • The nature and scope of the investigation
  • A list of requested taxa or materials with accession numbers

Loans are made for a specified period (usually six months). Loan extensions may be requested before the expiration of the requested loan period. When the loan is received, please notify herbarium staff either by email or by returning a signed and dated copy of the loan form via mail. If any loan materials are damaged in transit, please notify the Herbarium staff promptly and note the damage on the loan form.

Please notify the Herbarium staff by email when you are shipping loaned materials back to the ANSP. Please also do this if materials will be hand-delivered to the Diatom Herbarium by a person other than the loan recipient.

Publications Benefiting from Herbarium Use

The ANSP Diatom Herbarium materials should be cited with the accepted herbarium acronym (“ANSP”) in all publications. Please inform us of all publications that use/cite our specimens. We appreciate receiving reprints of papers based on ANSP specimens; these are deposited in the Herbarium Library.

Acquisition policy


The ANSP Diatom Herbarium acquires materials for the permanent collection via:

  • Field work by ANSP staff
  • Donations from individuals and institutions
  • Exchange with other institutions
  • Purchase


To be accepted for the permanent collection, materials must be of reasonable quality, include adequate documentation, have been collected in full compliance with all laws and regulations of the country of origin and the federal government of the United States.

  • The following documentation is absolutely necessary:
    • Geographic location (country, province, county, water body, etc.)
  • The following information is standard:
    • Title of the project
    • Collection date
    • Name of collector (or collecting agency)
    • Type of the sample/habitat (e.g., plankton, epiphyton, soil crust, fossil, etc.)
    • Original collection number
    • Detailed locality information (geographic coordinates, altitude, depth, etc.)
  • Optional, but desirable,information:
    • Water chemistry of collection site (pH, conductivity, etc.)
    • Taxonomic identifications
    • Count data

The information may be sent in any format, but electronic files are preferable.