Return to Native Trees of the Southern Rocky Mountains

Single-leaf ash is an ash tree with single rounded leaves, growing as a shrub or small tree, 6 to 25 feet tall, along streams and canyons in the desert sandstone country of western Colorado below 6000 feet elevation. It is much more common in Utah and northern Arizona than in Colorado, and may occur in extreme northwest New Mexico. It was one of the last native trees of Colorado to receive scientific attention, being discovered in 1859 and published in 1871. The scientific name is Fraxinus anomala , the anomalous ash. This ash is "anomalous" because its leaves are not compound as are the leaves of other ash trees.

Leaves: Single, rounded, 1 to 2 inches long, with smooth margins or sometimes toothed with a pointed tip. Occasionally as three-part leaves: three leaves attached to the same leaf stalk.

Stems: Four sided twigs.

Fruit: One-seed samara (flat and papery) 1/2 to 1 inch long and 1/3 to 1/2 inch wide, notched at the tip, are grouped in clusters.

Bark: Thin, dark brow tinged with red, in narrow scaly ridges.