The Elm Project, Part 3: Cedar Elm vs. Winged Elm

CEDAR ELM (U. crassifolia) vs. WINGED ELM (U. alata)
These two elms have small leaves, asymmetrical bases and (usually) double-toothed margins. These both can have corky “wings” on their twigs, so despite the name, you can’t identify a Winged Elm by these alone. However, Winged Elm usually has many winged twigs, while in Cedar Elm they occur mostly on young trees, and many large Cedar Elms have none at all. The ranges of these two overlap, but Cedar Elm’s range includes the eastern half of Texas, and it is much more common. (Cedar Elms are also popular as cultivated trees, but we’re mainly interested in the wild ones here.) Winged Elm’s range covers only the eastern quarter of Texas, so only part of North Central Texas. The trees range as far west as the East Cross Timbers region, which cuts through Denton and Tarrant counties.

1. The most sure-fire way of distinguishing these two is seasonal: Cedar Elm is the only native elm that flowers in the fall, and Winged Elm flowers in the spring. In North Texas, the small, round samaras of Cedar Elm are evident through most of September, and often hang on even later.
-- Here's an observation by @annikaml showing the autumn samaras of a Cedar Elm: https://www.inaturalist.org/observations/16108932
2. Winged Elm produces flowers and seeds in the spring, around March, before the leaves appear. Winged Elm is the only elm in North Texas that has corky wings on branches AND makes its seeds in the spring.
3. Cedar Elm leaves tend to be somewhat smaller than those of Winged Elm. Cedar Elm leaves are also stiff and thick, while Winged Elm leaves are thinner and smoother on top.
4. The leaf shape differs somewhat: Cedar Elm leaves are more rounded or blunt at the tip, while Winged Elm leaves are pointed at the tip.
5. The flowers and samaras of Winged Elm, like those of American Elm and Slippery Elm, appear in the spring before leaves open. They are fuzzy on both front and back surfaces, as well as having fine hairs extending from the margins. The samaras aren’t tightly clustered like those of the Slippery Elm, but don’t droop on long stalks like those of American Elm either.
• Here’s an observation by @lshepstew showing the springtime samaras of Winged Elm: https://www.inaturalist.org/observations/10521155

I’m working on a future journal dealing with the differences in twigs, buds, and flowers, but I’m still getting these sorted out. Hopefully in January!

Posted by lisa281 lisa281, January 01, 2019 22:29

Comments

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Thanks for putting this together, I always have problems with elm identifications.

Posted by annikaml about 1 year ago (Flag)
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You're welcome @annikaml -- it's helps me keep it all straight, too!

Posted by lisa281 about 1 year ago (Flag)
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Excellent work

Posted by lanechaffin 11 months ago (Flag)
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One of my early rude awakenings is that they both Cedar Elm and Winged Elm had winged twigs when young. Oh, darn! Thanks for the additional info. I'll charge out into the woods now to see which is now flowering - and which aren't. Keep up the good work.

Posted by joshmols 10 months ago (Flag)

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