Felger Herbarium’s scientific contributions

A floristic account is provided for the mustard and frankincense families as part of the vascular plant flora of the contiguous protected areas of Organ Pipe Cactus National Monument, Cabeza Prieta National Wildlife Refuge, and the Tinajas Altas Region in the Sonoran Desert of southwestern Arizona. The mustard family in the flora area includes 23 genera and 32 species; the majority are cool-season annuals (ephemerals). There are no hot-season annuals. Lyrocarpa coulteri and Hesperidanthus are the only mustards in the flora area growing during the warmer seasons. Among the 12 non-native species only 3 are established as reproducing populations in the flora area. Five species are represented in the fossil record. Sibara angelorum in Cabeza Prieta NWR is the only record for the United States. The frankincense family includes a single species (Bursera microphylla) in the flora area as well as in southwestern USA. This is the eleventh contribution for this flora published in Phytoneuron and also posted open-access on the website of the University of Arizona Herbarium (ARIZ). This contribution to the vascular plant flora in southwestern Arizona is the eleventh published in a series in Phytoneuron and also posted open-access on the website of the University of Arizona Herbarium (ARIZ). The area of coverage is that of the contiguous protected areas of Organ Pipe Cactus National Monument, Cabeza Prieta NWR, and the Tinajas Altas Region in the heart of the Sonoran Desert (Figure 1). Two eudicot families are included in this contribution: Brassicaceae and Burseraceae.