Multiple Uses Of The Herbarium

Science & Conservation

Tim Flynn

Herbarium Curator

Herbarium Curator Timothy W. Flynn is responsible for curating NTBGs herbarium (PTBG). This includes ensuring the collections and their associated data are well organized, updated, preserved and accessible for research and other uses.

Tim has been working at NTBG since 1981. In addition to curating the herbarium he has also participated in fieldwork in Hawaiʻi, Samoa, Tonga, Niue, the Cook Islands, Kosrae, Pohnpei, Palau, Australia, New Caledonia, and Ecuador. Tim has a special interest in collecting often overlooked non-flowering plants such as bryophytes (mosses) to ensure the collections are representative of the flora.


A herbarium is a repository for preserved plant collections or specimens, which serve as documentation of scientific collections and as reference for identifying new collections, or for teaching students about the plants.

Herbarium collections are always associated with a range of data about who made the collection, where and when, and other observations such as which type of environment the plant was found in and what the population size was.

NTBG field botanists are being very meticulous about recording as much information as possible about each new collection for later reference and all this associated information is documented on the label of each herbarium specimen as well as entered in the herbarium database.

The combined data from several collections can also be used to understand the distribution and character range of a species and observe changes over time as well as the composition of the flora in a specific area or point in time.

Researchers are for example increasingly using herbarium specimens and their data to learn about changes in flowering phenology in relation to bees and other pollinators, changes in species distribution and population size and how it may be correlated with changes in the environment to help guide conservation planning, or to understand the progression of an invasive weed.

Learn more about different uses of herbarium collections and their associated data here and through the links in the menu.

IUCN Red Listing of Threatened Species

As a member of the IUCN Species Survival Commission for Hawaii, NTBG uses the collection data to assess the conservation status of Hawaii’s flora. Information about distribution range over time determines if a species or taxon is to be considered Threatened by the IUCN Red List. NTBG has published assessments for all of Kauai’s more than 250 endemic species helping to increase international attention to the conservation needs of Hawaiian plants.

Rønsted et al. (2022). Extinction risk of endemic vascular flora of Kauai Island, Hawaii, based on IUCN assessments. 
Conservation Biology, e13896.

Type Specimens Document Species Names

Herbaria are permanent repositories for Type specimens, the exact individual plant that was used to define the species. Tetraplasandra flynnyii in NTBG’s herbarium (PTBG), was named after our curator Tim Flynn who discovered it in Kalalau Valley, Kauai in 1988. The name has since changed to Polyscias flynnyii when DNA analysis showed that the genus Tetraplasandra was part of the genus Polyscias. NTBG´s herbarium holds more than 315 type specimens.

Waiting 100 Years In A Herbarium For A Name

Rondeletia pringlei Lorence was collected by C.G. Pringle in Mexico in 1895 and named as a new species 100 years later in 1997 by NTBG’s senior research botanist David Lorence, while working on the treatment of Rubiaceae for Flora Mesoamericana. Herbaria are full of hidden treasures! David has also discovered several new species of Monimiaceae from Madagascar based on herbarium specimens sent to NTBG as gifts for identification by Missouri Botanical Garden.

Resurrecting Extinct Species

Conservation scientists are exploring the potential of resurrecting extinct species and populations from seeds in herbarium collections. Some archeological date palm seeds have been able to germinate after 2000 years, but generally seeds are better preserved in NTBG’s Seed Bank. NTBG researchers have tested the germination success of seeds from herbarium collections of Kauai´s 81 species having less than 50 individuals left in the wild such as this Dellisea kauaiensis.

Wolkis et al. (2021). Germination of seeds from herbarium specimens as a last conservation resort for resurrecting extinct or critically endangered Hawaiian plants. Conservation Science and Practice, e576.

Botanical Illustrations Accompany New Species Descriptions

In 2009, a new species, Stenogyne kauaulaensis (Lamiaceae) from Maui, was discovered by NTBG´s Ken Wood and Hank Oppenheimer from University of Hawaii´s Plant Extinction Prevention Program. The new species was only known from 15 individuals and is Critically Endangered, but successfully cultivated for conservation. While the Type specimen is housed in NTBG’s herbarium (PTBG), this beautiful art work by Wendy Hollender was used to illustrate the scientific publication of the new species.

Thousands Of Collections From Flora Of Marquesas

Herbaria serve as baseline collections and as repositories for the thousands of collections made during big regional Flora projects such as the Flora of Marquesas, a two-volume work summarizing 20 years of fieldwork by NTBGs senior scientist David Lorence and Smithsonian’s Warren Wagner. Remote oceanic islands are full of hidden biodiversity including many ferns. 85 new species were discovered during this work increasing the native flora with 25%, including this fern, Polystichum uahukaense, collected by Ken Wood on Ua Huka Island and described by David and Warren.

Our Collections

To learn more about our collections browse these pages. Some of our underlying databases are public. Access to the herbarium and library collections in the Juliet Rice Wichman Botanical Research Center for scientific or education purposes can be arranged. See contact information under each collection.

Public tours of NTBGs five gardens can be booked online. The Behind the Scenes tour, South Shore Kauai includes the nursery and botanical research center.

Our Areas of Focus

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