Cupressus Arizonica/ Hesperocyparis Arizonica
The Arizona cypress tree is native to very specific regions in North America. They will only grow in the southwestern United States, and they exist in very scattered populations rather than in significant stands.
This coniferous evergreen tree grows at a medium rate and is a rather short-lived tree — usually only living to be 30-50 years old. It is largely used ornamentally or as a sheltering tree in its native ranges.
We love trees so much around here that we’ve created a long list of 101 Types of Trees from all around the world. So once you’re done learning about the Arizona cypress tree, head on over there! We cover different pine species, cedar species, juniper species, and many more!
Related: Nootka Cypress Tree | Patagonia Cypress Tree
What do Arizona Cypress Trees Look Like?
Root System
Cypress trees will commonly grow rather wide-spreading and shallow roots because of their growing regions. In the case of the Arizona cypress tree, these trees maintain shallow roots because they are very resistant to drought conditions. These wide-spreading roots also help them maintain strength when subjected to storms and windthrow.
Dimensions
The Arizona cypress is one of the smaller cypress species, and this has a lot to do with the fact that they grow in desert conditions. Trees that don’t have much access to water don’t commonly grow to be very tall. The trunk diameter of Arizona cypresses is anywhere up to 55cm around.
Growth Pattern
Arizona cypresses have conic to ovoid conic-shaped crowns. They closely resemble the shape of a Christmas tree, and this is one of the main uses in their growing regions! When they receive enough water they will have very robustly shaped crowns, whereas with less water access they will be more scrappy looking.
Bark
Like other cypress species, the Arizona cypress is easily recognized by its bark. In older trees, they tend to grow bark that roughly shreds in narrow strips, and it is a gray/brown color.
Foliage
Arizona cypress trees grow foliage in very dense sprays. These leaves are needle/scale-like, and they will be either a dull gray/green color or a bright and glaucous blue-green color, kind of like a glazed blue appearance.
Each individual leaf scale is anywhere between 2 and 5mm long, and they grow in an overlapping arrangement that entirely covers the branchlets. These needles are soft to the touch and very aromatic.
How do Arizona Cypress Trees Reproduce?
Cones
Arizona cypress trees are monoecious, meaning that female cones and male cones will occur on the same tree. Cones are wind-pollinated, meaning that a pollen cone (male cone) will open upon maturity to release pollen which will be carried by wind to a seed cone (female cone) which will then become fertilized.
Seed cones (ovule producing) are globose to oblong in shape and are anywhere from 15 to 33mm in length. They possess 6-8 scales and will become mature about 20-24 months after the original time of pollination. They start out as a green color, then mature into a gray-brown color.
Pollen cones (pollen-producing) are also globose or oblong in shape, but they are far smaller, usually only 5mm long. They are the same color and will open up and release pollen between the months of February and March.
Fertilization
A fertilized seed cone will remain closed for a great many years, and will only open after the branch that is holding the cones is killed by wildfire. This is because seeds require mineral ash soil for germination. This is only good for local plant populations, as the Arizona cypress tree is able to repopulate an area after it has been devastated by wildfire.
What are the Damaging Agents of the Arizona Cypress Tree?
Many species of cypress trees are highly susceptible to the canker-causing fungus; seiridium Cardinale. This fungus tends to persist in areas that receive very hot weather in the summer, which is unfortunately very much the case in Arizona.
Once a tree has been infected with this fungus, it will not survive more than a few years. Thankfully since the Arizona cypress tree exists in such isolated pockets, the fungal infection is not able to travel very far and take out large groves of trees.
Arizona cypress trees are also damaged by the cypress bark beetle that will overgraze on its bark and foliage, making it even further susceptible to the fore mentioned canker causing fungus.
Where do Arizona Cypress Trees Grow?
It may seem obvious by the name that the Arizona cypress tree grows in Arizona, but their native range extends beyond this single state. Small populations of these trees are also found growing in other southwestern states, like Utah, New Mexico, southern California, Nevada, west Texas, and even down into Mexico.
The most impressive Arizona cypress grove is found in the Chisos Mountains that is in the Big Bend area of west Texas. Populations are commonly found growing alongside canyon live oak and California fan palm, which are trees that are also resistant to heat and drought conditions. They occur in USDA zones 7 through 9.
What are the Growing Conditions of Arizona Cypress Trees?
Soil
Arizona cypresses can tolerate many different soil types as long as they are well-drained. They can be found growing in loamy dry soil or sandy soil, and in soils that have either acidic or alkaline pH levels.
Sun Exposure
Like most other coniferous evergreen trees, the Arizona cypress tree is a sun-loving tree. It is not shaded tolerant whatsoever, which is a good thing considering the amount of sun it receives in its growing regions!
Water Level
The Arizona cypress tree is very drought tolerant, but it will be very happy and prosperous if it receives a minimum of 10 inches of water a year. This may not seem like a lot anywhere else, but that is a large amount of water in the desert.
How are Arizona Cypress Trees Used?
Wildlife
The seeds of the Arizona cypress tree are commonly eaten by squirrels and other small rodents.
Ornamental
Arizona cypress trees are very wind sturdy and therefore are commonly planted as a shelterbelt or windbreak tree. They grow successfully into hedges and are able to protect more delicate plants inside their garden perimeters. They are also a really lovely plant to use for the art of bonsai!