By Brandon Gallagher Watson
You, tree care professional and ardent reader of Arbor Age, are so good at tree identification that you would never need to carry an ID guide along with you, right? Well, sure, you can peg a buckeye from a horsechestnut at 100 meters in the fog at night, but let’s say for the sake of example your new hires are a little sketchy knowing their Ulmus rubras from their Ulmus americanas — are there any apps that could help them out in the field? The answer is yes, there are a ton of them. Are any of them any good? The answer is not many of them.
I’ve downloaded and tested no less than a dozen and a half tree ID apps over the past two years and have been awfully disappointed with most — including free apps, as well as apps for which I paid several dollars. Many rely heavily on leaf ID, which relegates them to only be useful in the summer, and others use so much botany jargon that they are pretty unusable to the average human. Some are decent for actual identification; others are better for learning more about the tree with info and photos once you know what it is. I haven’t found one yet that does all of these things great but the apps reviewed in this article have some merit and are worth checking out.
Available on: iPhone
If you actually need to identify an unknown tree in the field, nothing beats a dichotomous key. If you’ve ever used the one from Virginia Tech’s Department of Forestry, you know it is a simple-but-accurate key for figuring out the tree in question. The TreeBook iPhone app is pretty much the mobile version of that key. Open it up and it goes right to the “Identify” tab and has you choosing a leaf type to get started. You can also browse trees by common name or family, and the search function also searches all the different common names — making it a fairly good reference.
This app lacks the depth of photos found in other guides, and relies solely on leaves to start the key, so it has its limitations. Like many of the tree ID apps I’ve looked at, it has a definite East Coast bias for the species that are included, but for free it’s worth checking out.
Audubon Society Tree ID
Available on: iPad/iPhone
The Audubon Society is known for its high-quality and photo-heavy nature guide books, and this app is pretty much the mobile version of the tree guide. On the plus side, it does have thousands of detailed, high-res photos of the tree, fruit, bark and twigs of most trees, so it can be useful for helping determine which tree you are standing in front of. It has a Boolean-style “Search” function where you give it info on the characteristics you see and it tells you what trees fit that description. Additionally, it has a feature where you can add ‘Sightings’ of tree species you have seen. It will add a journal entry and geo-tag the location on a map for you, but do note that this feature requires the GPS, so if you do not have the 3G connection it will only work when connected to WiFi.
On the down side, it is a $5 app, but, considering the book runs $15 to $20, it is a fair price. The photo library is a little inconsistent as far as having all the diagnostic photos for every species, especially the more obscure ones where having more images would be most useful, but the photos it does have tend to look gorgeous. If you have the book already, this app doesn’t add much more than a pretty mobile interface. But if you ever need to show a tree photo to a client to help them understand something or just prove to them their maple is a Norway and not a sugar as they insist, this can be a handy app.
Available on: iPhone/second- and third-generation iPad
You walk up to a tree, pull off a leaf, and have no idea what species it is. Sure, you could use a key that makes you decide whether the underside leaf hairs are tomentose or pubescent, but who has time for that? Wouldn’t it be easier if you could just take a picture of the leaf with your iPhone or iPad and have it tell you what the tree is instead? Well, a team from Columbia University, University of Maryland, and the Smithsonian Institute thought, so and the result is LeafSnap. This free app is a whole new take on the tree ID concept, and is not only a useful tool but a gorgeous interface to look at and play with. Even if you are not using the leaf ID feature (like on my first-generation iPad with no camera) it is still one of the more enjoyable tree ID apps to use. You can tag the location where you found a tree, and other users can see those trees plotted on a map to check out nearby.
Although it is an awesome concept, it does have some points to consider. It works by basically scanning the outside shape of the leaf and comparing it to others in the database. This is easy for distinct leaf shapes (like a sweetgum) but a little harder for more generic shapes (like a cherry, plum, or apricot) but it often gets you close. The image snap can also read shadows as part of the leaf and misidentify things, so try to lay the leaf as flat as possible when shooting. The app does lack a full form shot of the mature tree but makes up for it with detailed images of key characteristics such as leaves, fruits and flowers. This app has a definite East Coast bias, as it was intended for Washington D.C., New York, and the Northeast, but rumor has it they are working to expand the database nationwide. Although it is not complete or universal yet, this app certainly shows the possibilities that mobile devices could bring to the field guide paradigm so stay tuned for further projects from this group.
Like any printed tree identification guide, ID guide apps will all have strengths and weaknesses. Considering there are plenty of choices for free (and even the paid ones are cheaper than a new book), check one out and see if you can find one that has the images, interface and utility that makes sense to you. Happy apping!
Brandon Gallagher Watson is director of communications at Rainbow Treecare Scientific Advancements, and is an ISA Certified Arborist (#MN-4086A).