As the natural history field trip was concluding, the group moved into a small clearing in the forest to hear final comments from the trip leader. Underfoot, slightly trampled and unrecognized, were a small group of Dwarf Pawpaws. The day would conclude without their appearance on any of the plant lists.
Overlooking Dwarf Pawpaws is completely understandable. They are inconspicuous, and blend in with the seedling and young sapling trees that dot the forest floor. As mentioned in Part 1, the flowers and fruit are uncommon and can be difficult to see even when present. As a consequence, most of the time identification relies on the leaves and twigs.
In the spring and early summer, the twigs of the Dwarf Pawpaw (Asimina parviflora) may have a distinctive yellow or light rusty color that is not present in the other neighboring plants. This characteristic varies among Dwarf Pawpaw populations, and tends to fade in the late summer and fall.
The Dwarf Pawpaw, like the Common Pawpaw (Asimina triloba), has a naked terminal bud, meaning that the leaf bud does not have protective scales or a cap; the tip of the leaf is exposed. This is perhaps the trait most specific to pawpaws and separates them from most of their neighbors. This trait can be difficult to see properly in the Dwarf Pawpaw without some magnification.
Persimmon (Diospyros virginiana) and Black Gum (Nyssa sylvatica) are two of the species whose young offspring are most commonly confused with Dwarf Pawpaw. In fact they are often confused with each other. Like most plants that grow on a mature oak-hickory forest floor, their leaves are wide and broad.
The following photos illustrate typical leaves of Persimmon, Black Gum, and Dwarf Pawpaw, with the first being Persimmon.
And finally Dwarf Pawpaw:
The three plants pictured above all have alternate leaves, smooth leaf surfaces and margins, and acuminate tips. They are all approximately the same size. It can be very difficult to tell them apart when walking through an area and just glancing down. It often requires a much closer look.
Below they are pictured side by side.
The two leaves on the left are Dwarf Pawpaw. They are more broadly obovate than the others and have a smaller acuminate tip. The widest part of the leaf is beyond the center and toward the tip.
The two leaves in the center are Persimmon. They are ovate, not obovate, with the widest part of the leaf occurring in the center of the leaf.
The two leaves on the right are Black Gum. They are variably oblong, but some may be obovate, as in the one on the far right. Black Gum leaves occasionally have teeth in the remote part of the leaf, and the acuminate tip is usually longer than the Dwarf Pawpaw tip.
The more plants there are in an area, and the more leaves they have, the more likely it is that a distinctive and recognizable trait will be seen.
In summary, helpful tips for identifying Dwarf Pawpaws are:
1 Unique flowers and fruit ( when present, which is rarely)
2 Bright yellow fall foliage
3 Bright yellow to rusty twigs in the spring and early summer
4 Naked terminal buds (Probably the best field trait)
5 Alternate, obovate leaves with smooth surfaces and margins, and a short acuminate tip
6 Primary habitat of dry, oak-hickory forests
At first glance, the understory of a hardwood forest may appear as a monoculture of small trees and shrubs. Taking a little time to learn plants like the Dwarf Pawpaw and its neighbors adds a new dimension to a walk through the woods and helps us to appreciate the diversity that can be found there.