These are the two tree species that first led me down the ELM rabbit hole. Trying to identify AMERICAN ELM vs. SLIPPERY ELM drove me crazy my first summer as a Master Naturalist. They both have larger leaves than other elm species that grow here, but it isn't really possible to distinguish these two using leaf size. Slippery Elm is named for the slimy "slippery" feel of the inner bark. That's a fine clue, if you can get to the inner bark, but I usually couldn't. Most of the time, the main thing I was using to differentiate them was how rough or smooth the leaf surface was. Slippery Elm is supposed to feel rougher to the touch than American Elm, but this isn't always easy to determine. American Elm leaves are especially variable, with some leaves feeling much rougher than others, even on the same tree. I spent the first months of the summer rubbing hundreds of elm leaves without ever being entirely certain on species. I really never made much headway that first summer, but over the winter I hit the books and found that there are actually a number of clues that are simple and clear enough to make sense to me. And these clues do not involve rubbing the elm leaves at all. (¬‿¬)

Here's my favorite: the leaves of Slippery Elm have secondary veins that are frequently forked: most leaves will have several forked veins on each side. In American Elm, the veins are rarely forked: most leaves will not have more than one or two per side. This often can be seen clearly in pictures, so is more helpful than texture! See pictures ---->> Slippery Elm on the left, American Elm on the right.
More leaf pictures: Slippery Elm on the left; American Elm on the right
Other hints: Slippery Elm leaves often taper abruptly to a very long tip, i.e. they are acuminate. They also tend to to be fuzzy on the back, with tufts in the man axils.
The leaf shape of American Elm is oval in outline, widest at the middle, tapering to a sharp, pointed tip.
Slippery Elm twigs are sturdier than American Elm, with large, blunt-tipped buds, chestnut brown and often covered in reddish fuzz. American Elm twigs are slender; buds are reddish-brown and pointed, with darker edged scales. LEFT PICTURE: Sturdier Slippery Elm twig on the left, next to American Elm twig on the right. RIGHT PICTURE: American Elm twig and buds
Most reliable way to identify these is with the fruit, a winged seed called a samara. Both American Elm and Slippery Elm flower and fruit in the spring, before leaves appear. In American Elm, both the flowers and the samaras hang in drooping clusters. The samara is elongated (longer than wide) and deeply notched. It is smooth and hairless on the front and back surfaces, but has fine hairs (cilia) all around the margin.
The flowers and samaras of Slippery Elm are in dense bunches, close to the branches. Slippery Elm has samaras that are round (about as long as wide) and are not deeply notched. They are hairless around the margins, but typically have fuzz on the front and back surfaces, especially over the seed in the center.
BACK TO: A Collection of Helpful Identification Guides

We now have a place to collect observations made by our members all over our area! We will be able to see the observations our fellow chapter members are making, encourage and appreciate what others are doing, learn from each other, build a sense of community. None of us can visit every single interesting place in our area, but we can visit them vicariously with our fellow chapter members. You do not HAVE to join the project in order for your observations to be included here. But you should join anyway, so you won't miss anything!

Whether or not you join the project, check back here often. We will be posting News that you won't want to miss.

Look for useful information:
-- tips on getting started on iNaturalist
-- advanced user "tricks" to be more efficient and get more out of iNaturalist
-- guides to interesting sites in our area
-- useful articles on identifying frequently confused trees (or flowers, or birds, or insects, etc. )
-- links to good resources for identifying a hard to ID flower, tree, bug, etc

We'll have things to put on your schedule:
-- upcoming BPTMN iNat survey outings you can attend
-- upcoming iNaturalist BioBlitzs in our area

We will even have some awards* and challenges for things like:
-- best observation of the week
-- Challenge: who can observe the most species in the month of ____
-- New User Milestones: make your first 10 or 100 observations

*sorry - no pin comes with these awards - although I do have a few iNaturalist bumper stickers we might give out for special accomplishments

This "vacant lot" sits near the entrance to our neighborhood, a place we've lived for almost 14 years. Although my husband and I have walked around this corner hundreds of times, until last summer we had never walked across it. Even after we started doing iNaturalist, we never walked across this field. It's slightly elevated, maybe three or four feet higher than the street, and you can't really see the top of it from the sidewalk. I cannot stress enough how unimpressive looking this little corner is! Not particularly bad: it was mowed if the grass got too high, no illegal dumping or anything. Just so completely unassuming that it was barely noticeable. Late last spring, we started using iNat to survey in the Stewart Creek Wetlands, which is just across the street from this little plot of land. Every week or two, we walked down to the Wetlands, walking right around this corner to get there. We made iNaturalist observations in the Wetlands, as well all along the roadside as we walked there. After we had made 4 or 5 of these trips, on one summer trip we decided to walk across this corner on our way home. I don't remember why we decided to walk across rather than around it; maybe it was a shortcut because we were tired. Right away we noticed an abundance of green milkweed. (Asclepias viridis) Sure, it's a common plant, but there's not much of it around this neighborhood, so it was a lovely surprise. What's more, we had already noticed that there was very little milkweed of any kind down in the Wetlands. So, it was good to know this patch was nearby.

Not long after this, though, we heard from the HOA property manager,Rhonda, that it looked as if the fire station was finally going to be built. We lamented the loss of all that milkweed, and explained the importance of milkweed to monarchs. Rhonda asked whether the milkweed could be rescued. Couldn't it just be dug up and planted somewhere else? We had no idea whether that was possible, but luckily, we knew just the person to ask! We went to Carol Clark, our resident monarch and native plant expert. She said, yes it could be done. It turned out that the people managing the wetlands very much wanted the milkweed, and were willing to help dig it up. Not only that, they had greenhouse space to nurse it over the winter, and expertise to help re-plant it later.

We were energized by the way the whole save-the-milkweed project was coming together, so we got serious about surveying this little field regularly. On Labor Day, we talked our son into going with us for our survey, and we found a plant we hadn't seen before. It came up on iNat as Whorled Milkweed (A. verticillata ) and we thought it looked pretty close, so that's how we id'ed it. By the time we got home, though, we had a correction from @milkweedguy. He identified it as Slim Milkweed (A. linearis) - which happens to be a very uncommon milkweed for North Texas. Carol asked for more pictures and sent them off to various experts; the experts had varied opinions. (Possibly my not-so-great photography skills contributed to the identification challenge.) Finally, Carol and a few others had to come see for themselves, and all agreed: it certainly appeared to be Slim Milkweed. We are still waiting on the final DNA analysis, but all the experts who have seen it themselves seem to be in agreement. It is indeed Slim Milkweed! It's hard to describe just how much FUN we had with this whole episode!! All right there in this incredibly uninteresting corner!

We've had two "milkweed pulls" and have rescued close to 600 plants. (Although I maintain that calling them "pulls" is very misleading! There is no pulling up these plants - it's definitely a DIG, not a pull!) Word is that the plants are doing well, and plans are in the works for planting sessions soon. We've found some other interesting plants here, including lots of Big Bluestem, several Gum Bumelias, lots of Gayfeather, to say nothing of all the butterflies, dragonflies, and other insects.

Because of iNaturalist, we stumbled upon some treasures that no one would have guessed were right there, waiting. Now, I can't help wondering what surprise could be hiding in any little patch of green I see!