North American Deserts
This collection builds on the Plants of the Mojave Desert collection to include specimens native to the other three deserts found in North America — the Great Basin, the Sonoran Desert, and Chihuahuan Desert.
Purpose and scope of the collection
This collection serves as a resource for studies of desert flora and their adaptations to arid climates. It also displays plants that are useful in urban residential, commercial, and public landscapes in the Las Vegas Valley and adjacent parts of southern Nevada with similar climatic conditions.
The Mojave Desert of southern Nevada, southern California, southwestern Utah, and northwestern Arizona is dominated by low, widely spaced shrubs. Most rainfall occurs in winter but summer thunderstorms occasionally occur in the eastern part. About three-fourths of the desert lies at elevations between 2,000 and 4,000 feet. The Mojave supports relatively simple plant communities with few trees, but the presence of the distinctive Joshua Tree (Yucca brevifolia) marks the boundaries of this driest of North American deserts (Mielke 1993; Taylor 1992).
The Great Basin sagebrush desert covers most of central and northern Nevada ad Utah, plus parts of California, Idaho, Montana, Oregon, Wyoming, Colorado, and Washington. Artemisia tridentate, tall sagebrush, is the most widespread, common, conspicuous, and ecologically important species. The Great Basin supports a high diversity of plant species owing to its vast geographical area which contains variations in elevation, topography, climate, and soil conditions (Taylor 1992).
A wide variety of plants forms and species characterize the Sonoran Desert. The saguaro cactus (Carnegia gigantea)i is the most recognizable of all Sonoran Desert plants. The abundant cacti, trees, shrubs, and perennials owe their existence to mild winters (some parts of the desert never freeze) and moisture received during two rainy seasons (winter rains and summer monsoons). Almost two-thirds of the Sonoran Desert lies in Mexico. In the United States, the desert lies in extreme southwestern California, Arizona, and extreme southern Nevada, mostly at elevations below 2000 feet (Mielke 1993).
Finally, shrubs dominate the Chihuahuan Desert, which occurs primarily in the Mexican states of Chihuahua and Coahuila, as well as west Texas, southern New Mexico, and extreme southeastern Arizona in the United States. Leaf succulents, like lechuguilla (Agave lechuguilla) and small cacti are common. Summer precipitation accounts for 70 to 80 percent of the Chihuahuan Desert’s annual rainfall. Elevations vary widely from over 6500 feet to about 1000 feet along the Rio Grande River. Much of the Chihuahuan Desert lies between 3500 and 4200 feet (Mielke 1993).
Collection — specific interpretations of this policy and special instructions
- Limit collection management to plants that are native to the Mojave, Great Basin, Sonoran, and Chihuahuan deserts.
- All North American desert trees should be accessioned as individuals within the Arboretum Core. Outside the Core, accession individual trees when they rare part of a limited population of the species on campus.
- Only a few individual shrubs of each species should be accessioned, but they should be from different parts of the campus.
- Emphasize plants suitable for Climate Zone 11 (Medium to High Deserts of California and Southern Nevada as defined in the Sunset Western Garden Book). However, utilize microclimates found on campus to support as wide a variety of taxa as practical.
- Plant specimens to simulate natural groupings wherever possible. Otherwise, group specimens according to their planting and culture needs.
Programs supported by the collection
- UNLV Biology: BIO 120 Plants and People, BIO 122 Desert Plants, BIO 148 Natural History of the Desert Southwest, BIO 345 Urban Horticulture, BIO 422 Taxonomy of Vascular Plants, BIO 426 Plant Anatomy, BIO 442 Principles of Plant Physiology
- UNLV Landscape Architecture: AAL 246 Plant Materials, second through fifth-year design studios (AAL 284, AAL 286, AAL 384, AAL 386, AAL 484, AAL 486, AAL 494, AAL 496)
- CCSN Ornamental Horticulture: OH 213B Drought Tolerant Landscape Plant Identification
Collection data
Type of collection: Geographic
Year established: 2003
Guidelines created: March 2006
Last revised: March 2006
Proposed by: 2003 Long Range Planning Committee
Location: n/a
Size: n/a
Amenities: n/a
Last inventoried: in progress
Number of species: n/a
Number of specimens: n/a
