SEX IN THE TREES

 She stood silently alone in the warm light of sunset, swaying gently from side to side, perfectly shaped, utterly dioecious! I walked up to get a closer look.

And she turned out to be exactly as expected…a beautiful Juniperus scopulorum, the canyon’s ubiquitous Rocky Mountain Juniper, and a beautiful lady at dusk.

 We usually don’t think of trees of being male or female, and we are usually right. There are no male and female Ponderosas Pines or Rock Mountain Maples. But it’s different for the Rocky Mountain Juniper.  These evergreens are found throughout the canyon, at least up to about 7500 feet in altitude. Often no more than a shrub, they can grow to bout 30 feet tall, have imbricate (overlapping) leaves and prefer dry, sandy soil.

 The females are easy to identify. The have pea-sized dark blue to light gray berries, which smell just like gin if squeezed. The berries of a different member of the juniper family are used to give gin its aroma and flavor. The males do not have the berries, but small light brown cones instead. At least they do until the cones fall off….but they never have berries.

 Why do some plants come in separate male and female versions? I expect it is a strategy to create healthier offspring by avoiding self-pollination. Other trees have different strategies for the same purpose. For example, our Ponderosas do not have male and female trees, but each tree has both male and female cones. The larger, harder, female cones that we are familiar with generally grow towards the top of the tree and smaller male cones (called strobili) grow towards the bottom. The pollen for these strobili can’t easily drift upwards to the female cones but is carried by the wind to other nearby Ponderosas.

There are other trees in the canyon which come in male and female versions. These include Aspen, Cottonwood and Willow.

 

 Please say “hello” to my sunset lady friend if you see her! There are lots of her girlfriends easily seen from the Roaring Creek Trailhead parking lot.