Anne Eisenberg reports on a prototype digital field guide, an iPhone app (from a team including Peter N. Belhumeur of Columbia Univ. and W. John Kress of the Smithsonian) that identifies tree species on the basis of scanning a single leaf specimen.
“We believe there is enough information in a single leaf to identify a species,” [Kress] said. “Our brains can’t remember all of these characteristics, but the computer can.”
We might call this an active field guide, as opposed to passive guides like National Geographic’s Handheld Birds for the Palm Tungsten platform, which leave the identification decisions to the user.
I’m skeptical. Plant identification is hard (at least it is for this birder), even though the plant just sits there, and you can examine leaves in the hand as long as you like. It’s not for nothing that the discipline has evolved elaborate ID keys that consider opposite vs. adjacent branching structures, leaf texture, bud scars, characteristics of flowers and fruits, geographic distribution, and more. Ironically, the screenshots accompanying the story demonstrate the identification of a leaf from that tricky genus, Quercus. A more realistic assessment comes from P. Bryan Heidorn with the National Science Foundation:
The computer tree guide is good at narrowing down and finding the right species near the top of the list of possibilities, [Heidorn] said. “Instead of flipping through a field guide with 1,000 images, you are given 5 or 10 choices,” he said. The right choice may be second instead of first sometimes, “but that doesn’t really matter,” he said. “You can always use the English language — a description of the bark, for instance — to do the final identification.”