As for whether the Herbarium was a standing set, I still say it was. I worked in the theater business building sets, so Iím very well aware of how sets are used and stored; and being an original TOS fan since the Sixties, Iíve certainly been around long enough to know how the Trek production handled their set requirements. So unless I see an original memo or an interview that says otherwise, Iíll remain unconvinced that it was anything other than a permanent addition to the other standing sets, as was the case with the auxiliary control room and emergency manual monitor.
Ralph Senensky, director of "Is There In Truth No Beauty?" had this to say in his blog:
"There were no locations required to film this episode. In fact the entire show would be filmed in the Enterprise
set on Stage 9 except for one four page scene in a herbarium set on swing stage 8."