Photo Gallery: What is a Herbarium Voucher?

At first glance, a herbarium voucher—which contains a carefully preserved plant specimen—may seem curious. What value could a preserved plant have?

These meticulously preserved vouchers serve as crucial repositories of plant knowledge. Each one not only documents the unique characteristics of the plant but also captures details about its habitat and the specific period in which it was collected. Together, the information preserved within a herbarium voucher provides invaluable insights for anyone seeking to deepen their understanding of a particular plant species and its ecosystem.

Browse through the photo gallery below to learn more about herbarium vouchers and their role in conservation efforts.

What is a herbarium?

Before delving into herbarium vouchers, let’s first explore what exactly a herbarium is. A herbarium is a scientific repository of permanently preserved plant specimens. Herbarium collections celebrate the richness and uniqueness of plant life, providing a window into various ecosystems and the complex relationships between plants and their environments.

Māmaki (Pipturus sp.)

What is a herbarium voucher?

Plants are a fundamental part of our world, deeply cherished and integral to our lives. A herbarium voucher is a portion of a collected plant (ideally with reproductive material) that has been carefully pressed, preserved (dried usually), mounted on archival paper, and stored in an herbarium. A well-made voucher will include comprehensive details about the plant such as its size, the location where the plant was collected, and other plants found growing nearby.

Hāpuʻu (Cibotium menziesii)

Why are herbarium vouchers important to make and maintain? 

In essence, herbarium vouchers serve as tangible records of plants. In working to understand and perpetuate a particular plant, having a point of reference is important. This is especially true when living plants are difficult to access, or when comparisons between individual plants from various locations or time periods are necessary for comprehensive study and conservation planning.

By continuing to maintain these collections and facilitate their accessibility, we ensure that future generations can benefit from the information preserved within these vouchers. This also enables us to support research focused on understanding and ultimately supporting plant life.

Dr. Tetsuo Koyama working on identifying Cyperaceae collections

How are herbarium vouchers used?

One of the most important ways herbarium vouchers are used is for correctly identifying plants. Similarities between certain plant species can often result in mistakes in identification. Having a voucher provides a tangible point of reference and ensures that a plant can be accurately identified. Also, scientists can’t officially document a new plant species without a voucher of the plant. Many new plant species are described long after they were first collected, and it’s estimated that there are thousands of plant specimens in herbariums waiting to be officially described!

In addition, researchers are increasingly using herbarium vouchers to learn about changes in flowering phenology (the timing of when plants bloom and produce flowers) as an indicator of climate. Vouchers are also used to understand changes in species distribution and population size and how it may coincide with changes in the environment. All this information can help guide conservation planning and efforts aimed at perpetuating plants that have important ties to place.

Are herbarium vouchers available to view online?

About 2/3 of our herbarium collection is digitized and searchable through our herbarium database. The herbarium is well updated and new specimens are added weekly! To learn more about our collections, visit our herbarium webpage.

Currently, our herbarium—along with Bishop Museum, the University of Hawaiʻi, and 27 other institutions—is partnering with the GLOBAL Bryophyte & Lichen Thematic Collections Network to digitize approximately 1.2 million moss and lichen specimens, making them available to researchers, teachers, students, and communities across the world. To see specimens that have been digitized so far, visit the GlobalTCN website and select National Tropical Botanical Garden.

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