Another sharp-eyed reader, Kevin Arthur of the fascinating Question Technology, has spotted another stock image breeding in the wild.
"Here is a trio that I just happened upon that use the same image of leaves," he says. "The last one is not a total match (it takes four of the five leaves and re-uses them -- I'm pretty sure they're the same leaves, though). The Walden edition I have a copy of and I think its design is excellent. The other two designs I don't much care for."
The original photo is by one Robert Holmgren, whose website has some lovely work on it. Here's a screen-captured sample (click for a big version).