How do live oaks have such variable leaf morphology?! Are there any documented variants?

[Veebs]

Here are some photos from this week on a trip down to Florida, all of live oak.

First, it seems some specimens of trees put out crazy new growth and other specimens right next door don’t. Same conditions.



You’ll see this repeated in big trees and small trees. Here are two branches from adjacent trees.


They can get massive like these which are probably 4-5 inches long:

And they can be tiny like these which are about three quarters of an inch

They can be long and spindly, straight or curved, wavy, or have slight teeth even after their juvenile state. Here’s all of those in one tree, and compare the size differences with the big and small ones above.

They’re literally all over the place.

What else is odd is that I get into groves that have way more gnarly wood with chopped up bark and a lot of round leaves that show no new growth and then groves covered with lot of fresh bright leaves that are all more variable shape and even though the trunks are bigger the bark is not nearly as rough.

But they’re all Southern Live Oaks it seems. But after this week I’m pretty suspicious that there may be subspecies out there after observing trees and sets of trees within the species that follow different behavior.

 

[Bonsai Nut]

I'm not sure those are Southern Live oaks. They look to me like Laurel oaks (Q. laurifolia).

 

[coachspinks]

Here is a link that helps explain the differences. The easiest way for me to guess, because I am never 100% sure, is by looking at the bark on the trunk. Live oak bark is much rougher. Live Oak vs Laurel Oak Often the variability can be attributed to the age of the tree and sun vs shade of the leaves. Lower branches of Water Oak trees often have leaves that are shaded and resemble live and laurel oak leaves.

 

[Esolin]

Coast Live Oaks are much the same way in terms of leaf variability. This is attributed to their propensity to hybridize and cross breed with other local oaks of similar ancestry. I assume they all get lumped into one species because they are close enough genetically that it's not worth trying to separate out dozens of subvarients by a few DNA markers when one Live Oak tree can theoretically produce any variant depending on local pollination. Live Oaks are promiscuous breeders with a rich gene pool.

 

[Michael P]

Live Oaks are promiscuous breeders with a rich gene pool.

That is a very polite way to say it.

 

[Veebs]

Here is a link that helps explain the differences. The easiest way for me to guess, because I am never 100% sure, is by looking at the bark on the trunk. Live oak bark is much rougher. Live Oak vs Laurel Oak Often the variability can be attributed to the age of the tree and sun vs shade of the leaves. Lower branches of Water Oak trees often have leaves that are shaded and resemble live and laurel oak leaves.

The evergreen part is the key in my opinion. These trees are all evergreens.

 

[Drcuisine]

Little slut trees.

In one of the pictures the leaves look similar to a Q Ilex or holm oak I have I’m growing. There are indeed fluid variations. My holm oak looks a bit atypical with more serrate appearance. Genetics and quality sourcing seems pretty important esp if we are propagating.