No source is given for this colorful 'Seki-joju' Azalea. My best guess is that the tree and photo are originally from Japan; it's not uncommon for Japanese trees to remain unattributed (this is often the case in the Japanese gallery section in Bonsai Today magazine back issues). We found the photo on Bonsai Addicted's timeline.

Yesterday we featured a magnificent root-over-rock bonsai by Marvin Besa from the Philipines. Here’s a post devoted completely to Root-over-Rock bonsai that we originally featured a year ago.

This Trident maple root-over-rock by Wolfgang Putz has to be on my top 100 bonsai photos list (if I had such a list). It originally appeared in a 2014 Bark post.

 Here's one that started as a root-over-rock and slowly morphed into a root-swallowing-rock (not an official designation, just an observation). It's another Trident maple (the most commonly used species for root-over-rock) originally from Kaede Bonsai-en.

Yet another Trident. You can imagine that if you removed the branch on the right and cut the one on the left back to where it emerges from the crown, this strange tree would look a whole lot more like so many other conventionally designed bonsai. But don’t do it!  Who wants a conventional bonsai when you have a tree so strikingly unique and impossible to forget? The photo is from the National Bonsai Foundation’s 2013 calendar.

 This unusual root-over bonsai with its dramatic gongshi type stone appeared in a post we did on Stewartias back in 2013. The photo is originally from Bonsai Today issue 24. Photo by Kindai Bonsai, courtesy of Bonsai Focus.