By BRUCE LUND
Some folks told me they liked the article on cottonwood tree buds a few weeks ago, and since it won’t be long until our few other deciduous trees start breaking their buds, I thought to do another story on one of my favorite trees –because its buds have a happy face – the Velvet Ash (also known as the Arizona Ash because most of its natural range is in that state).
The picture shows a handsome winter twig of a Velvet Ash. At the tip is a single terminal bud which encloses all the structural materials for the 2013 twig complete with leaves, flowers, and woody growth within overlapping reddish-brown scales. The pale half circle below the terminal bud is a leaf scar showing where last year’s leaf was attached to the twig and broke away leaving the hard pale scab which prevents underlying tissue from drying out. My favorite ‘smile’ is seen inside the leaf scar and is made up of a dozen or so ‘bundle scars’ that mark the places where individual food and water ducts transported food produced in the leaves back into the tree and water and minerals from the roots into the leaves.
Another distinguishing characteristic of Ash trees in the picture is the paired leaf buds on both sides of the twig. This is an uncommon arrangement in most deciduous trees where the leaves are arranged in a staggered or alternate pattern. This makes the bare branches of winter one of the easiest times of the year to recognize ash trees from a distance because the paired pattern extends to the twigs and branches and they stand out against the sky.
While Velvet Ash is native in southern Nevada naturally, it is not as well recognized as our much bigger Cottonwoods and Willows. All grow in river bottomlands along the Muddy and Virgin Rivers or adjacent to springs where their roots can reach groundwater, as at the Moapa Valley and Ash Meadows National Wildlife Refuges. Drivers on Rte. 93 pass through a large grove in Ash Springs past Alamo. And today, many people are familiar with ashes as lawn or street side trees where they do well because they are well watered.
Botanically, Ash trees are members of the Olive Family which also include such well known plants as lilac, forsythia, privet, jasmine, and olives. All these share the same family characteristics: they are all woody trees or shrubs (with a few woody vines thrown in) and virtually all have paired or opposite leaves.
Since Olive trees are fairly widely planted and probably better known than Ashes, you can see the leaf buds and twigs are in pairs on the twigs of one of your local trees. However, the leaf and bundle scars will be different because each olive leaf is a simple leaf around 2-3 inches long, whereas individual ash tree leaves are around 4-6 inches long and are subdivided into 3 to 5 leaflets – and multiple leaflets require a greater number of water and food tubes.
Bruce Lund is a retired biologist and has a lifelong love of nature instilled by his grandparents and some remarkable teachers. He has lived with his wife, Flo, in Moapa since 1997.
