Question: While walking through the Oxbow National Wildlife Refuge I spotted a young tree that I could immediately identify as Populus. …
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Question
While walking through the Oxbow National Wildlife Refuge I spotted a young tree that I could immediately identify as Populus. My first leaning was to P. grandidentata, but upon closer inspection of all of the leaves I began to wonder if this might be a hybrid. Could you offer your opinion on the likelihood of this being a hybrid versus displaying the expected morphological plasticity of bigtooth aspen? I've attached photos of all of the leaves. Thanks in advance!
Answer
Dear a_blooming_botanist, one of the trouble's that you will run into with the genus Populus (poplars, aspens) is that when the stems are cut the sprouts that emerge will have anomalous leaves. The reason is the root system is still intact and can supply more water and nutrition than the few sprouting leaves would normally have access to. As a result, these leaves are not constrained by size and surface area (normally, leaves maintain a certain size to prevent too much water loss). In the end, these leaves end up being very anomalous and are difficult to use for identification. Therefore, you have to rely on other characteristics such as branchlet pubescence and winter bud characters. Best wishes.
