While walking through the winter woods, I have seen these two trees which have red twigs. The one above . . . and this one . . .
The first image is of a sourwood (Oxydendrum arboreum). The second is red maple (Acer rubrum). Now, how to tell them apart? Let’s look more closely at each tree’s branching pattern, twigs and buds.
Starting with sourwood, this image shows a typical forking pattern for new branches:
The newer twigs coming off the prior growth’s branch are red. Also, notice the position of the twigs along the branch. They alternate along it.
This next image provides a closer view of a single red sourwood twig — which demonstrates one of the distinguishing features of sourwood. The top of the twig seems blunt or “cut off.” The length of the twig also seems a bit “zig-zag” with the way the leaf buds and leaf scars are aligned along it.
Here’s a closer view of a blunt sourwood twig tip . . .
Another closeup of a twig tip — with a “bump” for a leaf bud.
And one more closeup of a sourwood twig tip — this time with a leaf bud of a slightly different shape . . .
You can also see the leaf scar from last year’s leaf — just below the new leaf bud.
This last sourwood image shows the leaf scar further down the twig, along with a leaf bud which looks like a cap on top of the leaf scar.
Turning to a red maple, here’s a branch with newer twigs coming off it.
A closer view of another red maple branch and twigs . . .
Notice the arrangement of the twigs. They are opposite each other. In fact, they alternate their “oppositeness” along the branch. The botanical term for this branching pattern is “opposite and decussate.”
You can see this clearly in the two red maple images above as well as in the next image.
The above image shows a couple things. First, the twig is quite straight along its length. Second, can you see how the red maple twig tip looks more pointed while the sourwood twig tip looked blunt?
The tip of the twig above has buds clustered more closely together than the next red maple twig tip.
Here’s an even closer look at a different red maple’s pointed tip. You can see how the scales overlap in a lovely pattern.
This final red maple image shows the buds further down the twig. They are located above the leaf scars — which are relatively smaller than sourwood’s leaf scars.
I’m sure there are more ways to distinguish between these two trees. For me, when I’m enjoying that winter woods walk and I see some red twigs, I look for:
(1) the overall shape of the twig (straight–red maple vs. “zig zag”–sourwood),
(2) the shape of the twig tip (pointed–red maple vs. blunt–sourwood) and
(3) the bud position (opposite–red maple vs. alternate–sourwood).