An Anomalous Fraxinus anomala
Craig Holdrege
From In Context #36 (Fall, 2016) | View article as PDF
In the spring of 2016, Henrike and I were hiking in the canyonlands of southern Utah. The immensity and beauty of this rock-dominated landscape were almost overwhelming, since no two canyons were alike. And the presence of each place changed throughout the day with the rising and sinking of sun and the play of clouds. The plants were often spaced and arranged as if a gifted and aesthetically minded gardener had been hard at work.
Figure 1. Singleleaf Ash shrub (Fraxinus anomala).
One rather inconspicuous shrub caught my attention. It grew between four and eight feet high with many branches and small round leaves (Figure 1). Noticing fruits on some of the shrubs, I looked more closely (Figure 2). To my amazement, I recognized the fruits as ones I knew as belonging to ash trees (the genus Fraxinus, Figure 3). Later I saw specimens with flowers that were also characteristically those of an ash. But ash trees always have divided leaves — so I thought — and the leaves of these shrubs clearly had simple round blades and long leaf stalks.
Figure 2. Branch from same shrub showing simple, round leaves and dangling fruit.
So back at our campsite I consulted a field guide and, yes, the shrub is an ash: Fraxinus anomala; its common name is Singleleaf Ash. The species designation “anomala” refers to the fact that its simple round leaves set it apart from all 65 other ash species. I enjoyed coming across this anomalous ash tree as we hiked through the canyons and over the ridges and plateaus — I’m thrilled by exceptions.
Figure 3. Branch of a white ash tree (Fraxinus americana) with leaves and fruits (left), and a single divided leaf (right), which is the typical form of leaves in ashes.
Figure 4. All the leaves at the end of this branch were divided, most having three leaflets.
On a subsequent hike, the anomalous ash outdid itself. One single specimen had a few branches with some divided leaves (Figure 4 and 5). An anomalous Fraxinus anomala! Here the “ashness” of its fellow species broke through and showed itself. What a revelation.
While this shrub normally keeps to its tendency to make simple leaves, it also has the potential to do differently and suddenly resemble its Fraxinus relatives. It was a joy to witness this species “being itself differently,” to use Henri Bortoft’s phrase. I kept an eye out for this shrub on the rest of our hikes and never again did I encounter an anomalous Fraxinus anomala with divided leaves.
Figure 5. the two leaves that are unfolding at the end of the branch are divided (three leaflets each), while the leaves lower down on the branch are typical simple leaves.