Scientific Name
Hesperocyparis arizonica
The Arizona cypress is a western conifer whose main native range lies in northern Mexico, with additional populations in New Mexico and Arizona. To grow it successfully along the Front Range, seed was collected from high-elevation stands in New Mexico. One important source was Cookes Peak, at 8,404 feet, where trees experience colder and more challenging conditions than in much of the species’ range. That provenance became the basis for the tree now growing on campus, donated to Regis by the late Dr. Allan Taylor of Boulder in 2017. It was first established in the Regis tree nursery and later transplanted to its permanent location on the Commons in 2022. Larger, older specimens can also be seen at the Denver Botanic Gardens. Because of its limited natural range in the United States, some conservationists have suggested it could be a candidate for assisted migration if native populations begin to decline under climate stress.
Arizona cypress forms a narrow, pyramidal outline and can be expected to reach about 30 feet in our region. Colorado’s current champion trees reach up to about 40 feet and have likely approached their mature size. The foliage is made up of small, scale-like leaves that often show a striking silvery blue color, though there is noticeable variation among individuals and cultivars. The branching pattern is very regular and finely structured, almost mathematical in appearance, sometimes bringing to mind snowflakes or fractal designs.
The seed cones are about an inch across and have a rounded, “soccer ball” appearance, similar to those of bald cypress.