Next Big Step – Identifying Oaks!

As I’ve previously mentioned, each year of this project, students have been able to figure out how to identify more and more species, especially juvenile individuals. The next genus I plan to attack is the oak family (the genus Quercus). There are 10 species of oaks in the College Woods, and while some are more common than others, it is still difficult to tell the species apart in juveniles.

This is one of the individuals I'm unsure about. The light color and thinness of the leaves makes me think White Oak, but the pointed lobes are closer to Northern Red Oak.

This is one of the individuals I’m unsure about. The light color and thinness of the leaves makes me think White Oak, but the pointed lobes are closer to Northern Red Oak.

So far there are a few distinguishing features: pubescence on leaves and petioles, bristle tips on the lobes, and thickness of the leaves. If there are bristle tips and the leaves are pubescent, it is either Black Oak (Quercus velutina) or Spanish Oak (Quercus falcata). As they get older, Spanish Oak juveniles develop three distinctive lobes, but so far they don’t seem to start out with them. If there are bristle tips but no pubescence, it is most likely Northern Red Oak (Quercus rubra), but as juveniles they seem to be difficult to distinguish from White Oak (Quercus alba), which has neither bristle tips nor pubescence. This doesn’t even cover the other six species in the College Woods.

Here you can see the beginnings of the three lobes that mark this plant as juvenile Spanish Oak. The dark, shiny leaves and pubescence help confirm that.

Here you can see the beginnings of the three lobes that mark this plant as juvenile Spanish Oak. The dark, shiny leaves and pubescence help confirm that.

If I can’t figure it out just by looking at juveniles in the woods, my next step is going to be growing oaks from seed in the greenhouse. By being able to closely observe all of the developmental stages in a close setting and taking pictures I can go back and study later, I should be able to find some patterns. I may also need to go back to the herbarium to see what oak specimens they have. My goal is to figure this out before next year’s research students start working on this project.

Considering this plant's pubescence and dark, shiny leaves, it's probably a Black Oak. Unfortunately, I can't be sure until this plant gets a little older, because Spanish Oak looks similar and their leaves don't seem to get their lobes right away.

Considering this plant’s pubescence and dark, shiny leaves, it’s probably a Black Oak. Unfortunately, I can’t be sure until this plant gets a little older, because Spanish Oak looks similar and their leaves don’t seem to get their characteristic lobes right away.

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