Figure 1: The 3 lobed leaves of Acer negundo.
Figure 2: Striated bark of Acer negundo
Figure 3: Acer negundo seeds
Boxelder bark has the tendency to be more striated than that of the Acer grandidentatum. Though rougher in texture than that of other maples it is not as rough as species like the walnut. (See figure 2)
The reproductive structures are very similar to those of the entire maple family. The helicopter shaped seeds are great for short distance dispersal. These structures develop in bunches. The size of the bunch depends on the water availability. In dry years less seeds are produced thus a bunch size reduction is seen. (See figure 3)
These trees do not only reproduce sexually. Since Boxelders grow in areas with a fair amount of seasonal unpredictability, they also reproduce asexually or clonally. This clonal reproduction causes them to grow in large clumps that appear like a single tree with several trunks. The seasonal unpredictability causes an uncertainty in the ability for the next generation to establish thus making it easier to reproduce asexually to eliminate this problem.
Boxelders are considered a riparian species. This means that they grow near a river or water source. The tendencies for Boxelders to grow near to a water source along with its methods of reproduction make it easy for them to live to 100 years or more.
These general characteristics are easy to see through the data collected by The University of Utah’s Fall 2007 Biology 5465 class. Of the 151 trees evaluated in Red Butte Canyon only 60 were female. This data shows a reduction in females compared to the data found by the previous class; thus showing a reduction in reproductive structures due to drought.
The age was calculated based on the Diameter at Breast height. This data shows the age span of the trees.
