The Plant Resources Center (TEX-LL) with over 1,000,000 specimens is the largest herbarium in the southwestern United States and ranks fifth among U.S. university herbaria and twelfth across the nation. TEX-LL, with about a quarter of its specimens from Texas, has the largest holdings of Texas plants in the world. Nearly one half of the specimens at TEX-LL are from Latin America, with an especially strong representation of Mexico and northern Central America. Presently the number of vascular plant collections inserted in the herbarium is growing at an approximate rate of 16,400 specimens per year.
PRC publishes Lundellia, a journal of botanical systematics annually with contributions by faculty, staff, students, and collaborators.