I have been told that Ash Logs can be found on cacti in Drybone... I'll admit, I didn't think to check for that. I deliberately avoided cacti when I was looking Ash Logs. Once I'm done with that, I'll just do another complete logging rundown of Emerald Moss checking for Lavender (I don't think I hit every possible tree the first time through).

Currently, I'm on vacation, so it probably won't get done for a week or so.