If you’re like me, you frequently spot curious-looking trees on a hike, wonder what they’re called while looking at the leaves and flowers, then forget about them — only to repeat the cycle again the next time you see them. Now comes an iPhone app that’ll stop the wondering cycle: The Arbor Day Tree Identification Guide: What Tree Is That?

The app is the mobile version of the Arbor Day Foundation’s book, “What Tree is That?” published in 2009. Just like the book, the new digital iPhone-friendly version lets you easily identify North American trees by noting the characteristics of the leaves and branches with the help of color illustrations.

Plus, the app lets iPhone and iPod Touch owners geo-tag the tree they’ve identified using iPhone’s global positioning system. Find it at iTunes for just $4.95 — a nice savings from the $14.95 sticker price for the book version.

Not an iPhone user? Arbor Day does offer a somewhat jankier mobile version of "What Tree is That" that works for other smart phones. It’s what I would use, except I’m trying to get into the habit of taking a break from my phone when I take a hike….

Identify trees with your iPhone
Arbor Day Foundation iPhone app lets you identify trees on the go -- and even geo-tag them to start a national tree inventory system.