Ask Mr. Smarty Plants

Let's begin by establishing what is meant by "indigenous." According to the dictionary we referred to:

Indigenous means: belonging to a certain place.  Indigenous species are those established in a given region, having originated there, or been long settled without human intervention. The Lady Bird Johnson Wildflower Center and Mr. Smarty Plants are dedicated to the growth, protection and propagation of plants native not only to North America but also to the area in which the plants are growing. There are always arguments about how far back you have to go in botanical history for a plant to be "native" to the place where it is found, but the definition for "indigenous" as being long established in a region without human intervention would seem to cover the situation you are asking about.

Next, we'll try to decide if the Mediterranean Pencil Pine got to the Verde Valley in Arizona without human intervention. We found two members of the Cypress family that are sometimes referred to as pencil pines. Both are part of a group of plants called conifers, which are gymnosperms.

Athrotaxis cupressoides- endemic to Tasmania in Australia, meaning it grows nowhere else in the world naturally

Cupressus sempervirens-The vast majority of the trees in cultivation are selected cultivars with a fastigiate crown, with erect branches forming a narrow to very narrow crown often less than a tenth as wide as the tree is tall. If this is the tree you are seeing, it isn't native to anywhere, since it has been developed into a specific shape and growth pattern by human intervention. This article from Floridata says that it occurs naturally in southern Europe and western Asia.

Our guess is that what you are referring to is the Cupressus sempervirens, or one of the cultivars of that plant. We believe we have established that the trees you are talking about are neither indigenous nor native to Coconino nor Yavapai counties in Central Arizona. The reason there are so many of them is that they can survive in the Arizona climate, grow tall and thin for privacy purposes and are no doubt vigorously marketed by area nurseries.

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