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By Craig Huegel Reprinted from The Understory, Mar.-Apr. 1993 I spent my earliest years in my grandfather's house in an older neighborhood of Madison, Wisconsin. Like many similar neighborhoods, the street was lined by American elms so tall that their delicate branches arched up and over the blacktop, shading all below them. In the summer, their branches were the choice location for nesting orioles and I awaited their arrival each spring to watch in amazement as they once again wove those pendulous baskets that would house their eggs. Today, those stately trees of my childhood have been lost to exotics: Dutch elm disease introduced by European beetles. But I have many fond memories tied to elms and a continuing soft spot for them. True elms belong to the genus Ulmus and are common throughout the northern hemisphere. They also are commonly used as shade trees in developed landscapes. Their numerous pendulant branches also provide a great many nesting sites for birds. Elms are deciduous and most common to fertile moist soil habitats. They are not tolerant of salt, but are quite adaptable to most other growing conditions. The flowers are perfect (they have both male and female parts) and they occur in short racemes that certainly are not showy. Nevertheless, they get the job done and the small winged seeds ripen about a month later. At first glance, these dry seeds would not seem to be of much food favlue to wildlife, but because most elms produce their seed in early spring when other foods are scarce, many birds and small mammals eagerly seek them out. Although elms produce good yellow fall color farther north, they are disappointingly bland here in the Pinellas County area. The leaves are attractive at other times, however. Slightly asymmetrical and oval in shape, elm leaves are characterized by their many-toothed margins and their deep green color. In most years, elms are leafless here for only a brief time during the middle of winter. Four species of elms are native to Florida, but two of these are uncommon residents to parts of north Florida and may not be well-suited to Pinellas County landscapes. Cedar elm (U. crassifolia) is a medium-sized tree adapted to alkaline upland soils and shares with the winged elm the trait of producing corky wings along its branches. It is unique among native elms in that it flowers and fruits in fall. Slippery elm (U. rubra) is a common component of mesic bottomland forests throughout the East, but it occurs in Florida only within the Panhandle. Two other natives are found naturally in cenral Florida and are excellent landscape choices here; Winged elm (U. alata) is a large (up to 100 feet) distinctive tree native to upland wooded areas. Named for the numerous and showy corky "wings" that adorn its branches and trunk, this tree is one of those rare species that remains as attractive after leaf-fall as before. Because this occurs naturally in upland site, winged elms are drought tolerant and adapt well to most landscape situations without stress. It also is resistant to Dutch elm disease. At present, this tree is under-used in developed landscapes, but its beauty and adaptability give it great potential. American elm (U. americana) is the other species native to this country. It is a 70-foot tall tree and native to moist soil woodland areas. Although populations of this elm have been devastated by disease in the North, it has not yet been a problem in Florida. Two subspecies occur in Florida: the americana one found in north Florida and typical of the species to the North, and the floridana subspecies found throughout north and central Florida. This latter subspecies often is referred to as "Florida elm." American (Florida) elm is adaptable to the average landscape setting here in Pinellas and should be more widely used than it is. |
