Project Spotlight – North Texas Master Naturalist Dallas County Herbarium

NTMN Dallas County Herbarium

Carolyn Rozier

What is a Herbarium?

It is a collection of dried plants. It has also been called a dry garden or a winter garden. In the 1400’s dried plants were pasted in books.  Carl Linnaeus who systematized plant names also systematized the pressing and drying of plants.  He collected dried plants and the ‘herbarium’ was created.  Now the term refers to a museum of preserved plants that are used for botanical research.

There are over 6000 Herbaria in the world and over 600 in the United States. The largest Herbarium is at Kew Gardens in England, which houses over 7 million specimens from all over the world. Many of Linnaeus’ specimens are housed at the Linnaean Society in London. The Missouri Botanical Garden houses over 6 million specimens and is of particular interest to Texas because many of the botanists who collected plants in Texas in the 1800’s sent their specimens to Missouri.

In Texas there are the Plant Resources Center at the University of Texas, the Tracy Herbarium at Texas A&M, and the Botanical Research Institute of Texas (BRIT) in Fort Worth. Many of the smaller herbaria were given to BRIT so that it houses over a million specimens. Then there is the NTMN Dallas County Herbarium, located right here in Dallas. We have collected over 1400 specimens of Dallas County plants with 1/3 of these going to BRIT.

Specimens and Purpose

What is collected for a specimen? The whole plant or part of a plant can be collected. It is ideal to have roots and flowers or seeds. Large or tall plants can’t be collected whole but representative leaves or flowers can be collected. Some herbaria

can store large dried parts such as palm fronds and some flowers can be stored in formaldehyde. Also collectors insure that they don’t dig up all the representatives of a plant in a certain area. For the NTMN Herbarium three of each type of plant are collected. One becomes a permanent specimen, one an educational specimen and one goes to BRIT.

What are the purposes of herbaria? The specimens housed there can be used for reference to identify other plants and can be used to determine the distribution of species as well as variations in species. Variation in times of flowering or fruiting can be noted over time as species can be compared over many years when specimens were collected.

Also data on plant diseases or insect damage can be available as specimens are collected as found with such damage. Research is a major purpose of herbaria as material is available for DNA analysis, for biodiversity research and for chemical analysis related to climate change.

What is the purpose of the NTMN Dallas County Herbarium? It is to provide educational specimens of plants of Dallas County. To support this purpose, we provide educational specimens that can be checked out to teachers, speakers or groups who want to learn about plants native or endemic to Dallas County.

History of the NTMN Dallas County Herbarium

The idea of this herbarium was the vision of Jim Varnum. A committee of members got together five years ago to learn about what was necessary to start such a project—Anne Curtin, Gail Kahle, Melissa Martin, Carolyn Rozier.

A cabinet for storage was given to us by BRIT and our specimens are housed there in the Extension Office at Marsh Lane.

Many other volunteers have joined us and collection at Big Spring was a 2014 class project.

Processing Specimens

What are the jobs necessary for the herbarium? There are several steps in the process of actually putting a specimen in the herbarium. The first step is to find and collect the specimen.  For this task volunteers are needed who are able to identify plants, then volunteers who can dig the plants, and volunteers to press the plants. Information needs to be collected such as where and when collected and type of habitat. After the plants have been pressed and dried then volunteers must identify the specimens. Usually we have a tentative identification when the plant was collected but it must be verified by someone else. The next step is to enter the specimens into our database followed by printing of labels to go with each specimen.

 Another group of volunteers is needed to mount the specimens on herbarium paper with the labels. The mounting is done on special acid free paper. As mentioned we collect three of each specimen if possible because we have one specimen that goes into our permanent collection in our herbarium cabinet. This specimen is on 11 1/2 inch by 16 ½ inch acid free paper.

This special size has been used since Linnaeus and has to be purchased from a herbarium supply company. A second specimen is for education and is on 8 ½ by 11 inch acid free paper and is placed in a plastic sleeve and kept in notebook binders. The third specimen is sent to BRIT for that collection. Special glue developed by the Missouri Botanical Garden is used.

A librarian then files the specimens by family in the cabinet and in the notebooks. The storage is arranged by family. For instance, if the specimen is a dandelion, the scientific name is Taraxacum officinale which is in the Asteraceae family. If you want to check if we have a specific plant in our collection you can go online to and you can enter the scientific name or the common name. However since there may be many common names for a particular plant it is best to use the scientific name. Another way to find our list is to go to, choose About then Links we like then NTMN Dallas County Herbarium.

We want our collection to be used and to that end we have compiled notebooks of Medicinal Plants and Invasive Plants.  Teachers and others who would like to use our specimens should contact Carolyn Rozier at

We also need volunteers to continue to add to our collection.  Right now our most immediate need involves people who can identify plants in the field and who know a particular area in Dallas County.  Then we need people who collect and press.  If you wish to be added to the email list of volunteers who want to be notified about herbarium activities please email Carolyn.

Comments are closed.