The first botanical specimens at The University of Texas were deposited in the 1890's, although it was not until the end of that decade that the first botanist joined the University. The first curator was Dr. Mary S. Young, an enthusiastic and adventurous collector, who took charge of the herbarium in 1912. During the summers, Young traveled to west Texas collecting in the Guadalupe, Chinati, Davis and Chisos mountains, amassing the largest collections of west Texas plants since those of Charles Wright during the United States - Mexican Boundary Survey in the 1850's. She also collected less intensively in many other parts of the state. Dr. Young increased the herbarium holdings from 2,500 specimens to 16,000 at the time of her death in 1919.
For the next 45 years (until 1958), the herbarium was directed by Dr. Benjamin Carroll Tharp, who shaped the herbarium's growth from 16,000 to 200,000 specimens and collected extensively in Texas. In 1945, Dr. Fred A. Barkley became the new curator of the herbarium, the first curator in many years. Although he was curator only until 1948, he had a major effect. He pursued an active collecting program in both Texas and Mexico and initiated exchange programs with other institutions, thereby greatly increasing the herbarium's Latin American holdings. After he left, there was no curator again until 1975.
In 1958 Dr. Billie L. Turner took the helm of the TEX herbarium, subsequently the Plant Resources Center. In 1961 Marshall C. Johnston joined the Botany faculty. Through the combined efforts of Turner and Johnston and their students, the holdings of the herbarium increased by 100,000 sheets between 1964 and 1970, bringing the total to 300,000 by 1970. In the mid 1970's the Plant Resources Center, an independent research institute in the College of Natural Sciences, was formed to encompass The University of Texas Herbarium, the Lundell Herbarium, a program on the rare and endangered species of Texas, and associated laboratory facilities. In 1978 Dr. Beryl S. Simpson joined the Botany faculty; she assumed the directorship of the Plant Resources Center upon Dr. Turner's retirement in 2000, and Dr. José Panero, an Asteraceae specialist on the faculty since 1996, became the Associate Director.
Through the last half of the 1970's and the 1980's, Dr. Cyrus Lundell, formerly Director of the Texas Research Foundation and then Professor at The University of Texas at Dallas, transferred his herbarium of 315,000 sheets to The University of Texas. Dr. Lundell's collection is one of the richest in the world of material from Mexico, Guatemala, Belize and Honduras, as well as Texas. In 1991, the Moldenke collection acquired by Dr. Lundell of over 3,500 collections of Verbenaceae and Eriocaulaceae was also transferred to the Plant Resources Center making The University of Texas one of the strongest collections in the world in these families. The Plant Resources Center now houses a total of over one million specimens of vascular plants.