Aztec Ruins National Monument - Plants

The irrigation ditch supports exotic species that require more water than is available in drier locations, but it also provides habitat for native riparian trees and herbaceous perennials. Where the arroyos or washes slope down to the ditch, riparian and semi-riparian species also occur, along with several exotic species. The slopes and uplands north of the main archeological sites support a rich plant community of native grasses, herbaceous perennials, annuals, cacti, and shrubs. Non-native plant species are numerous and abundant in some areas, particularly along the irrigation ditch, and around the park headquarters, the large prehistoric structures, and the orchards and formerly cultivated fields. Tumble mustard occurs in many places. Hoary cress and Russian knapweed, noxious weeds that are very competitive with other species, occur in several areas of the park. Disturbance associated with previous agriculture—croplands, orchard, pastures—coupled with the disbursal of exotics via the irrigation ditches have contributed to the establishment of exotic species within the park. No federal or state listed species of concern are present. Botanists have recorded eleven vegetation types, including pinon-juniper woodland, grasslands, and riparian vegetation.