Characteristics of L. mackii
In the area in which we will be working, it will be relatively easy to recognize L. maackii for one simple reason: the many of the shrubs and small trees that we will see will be L. maackii. L. maackii shrubs often have multiple trunks originating from the same root system, so a shrub often appears as a "clump" with stems arcing outward from the base (see Fig 4.A. as well as the shrub being removed by students in the picture in the historical background). The bark of larger shrubs also has distinctive rows of parallel vertical cracks extending along the trunk. These cracks have been described as "cat scratches" (see Fig. 4.B.).
Fig. 4.A. Lonicera maackii in early spring. B. Vertical cracks in L. maackii bark. Images from http://bioimages.vanderbilt.edu/baskauf/17657, http://bioimages.vanderbilt.edu/baskauf/17370, and http://bioimages.vanderbilt.edu/baskauf/17665
Smaller L. maackii individuals do not display the characteristics described above. However, they can still be easily distinguished by the characteristics of their leaves and buds. The most obvious trait of L. maackii in the early spring is that it develops leaves far earlier than most of the native trees. By early March its buds are swollen and ready to open, and by the latter part of the month the leaves are already expanding (see Fig. 5). Most of the native trees and shrubs do not produce leaves until mid-April.
Fig. 5.A. Lonicera maackii twig with buds, March 13. B. L. maackii twig with expanding leaves, Mar. 19. Images from http://bioimages.vanderbilt.edu/baskauf/17365 and http://bioimages.vanderbilt.edu/baskauf/17661
Fig. 6. Full expanded L. maackii leaves showing opposite position on twig and tapering leaf tip on an individual leaf. Images from http://bioimages.vanderbilt.edu/baskauf/11045 and http://bioimages.vanderbilt.edu/baskauf/29632
The leaves of L. maackii are arranged oppositely on the twig (as are the buds) and the tip of an individual leaf tapers to a narrow point (Fig. 6). These characteristics help to distinguish L. maackii from two other common shrubs found in the plot (Fig. 7): Symphorocarups orbiculatus (coralberry) and Lindera benzoin (spicebush)
Fig. 7.A. Symphorocarups orbiculatus (coralberry) B. Lindera benzoin (spicebush) Images from http://bioimages.vanderbilt.edu/baskauf/17137 and http://bioimages.vanderbilt.edu/baskauf/11019
Like L. maackii, S. orbiculatus leaves are arranged oppositely on the twig, but S. orbiculatus leaf tips are rounded (Fig. 7.A.). Like L. maackii, L. benzoin leaves have pointed tips, but L. benzoin leaves are arranged alternately on the twig (Fig. 7.B.). They also have a pleasant, spicy smell when crushed. There are a very large number of S. orbiculatus shrubs to the north and west of quadrat C9, so don't be fooled by them, particularly if you are working in the northern part of the study plot.
