I know this thread is a year old but I just ran into it. "The Century Plant" was co-written by my great uncle, Bob Miller. The actual title was " She Waits and Waits". as far as I know it was never released under the Century Plant title. I do have a copy of this 78rpm.
It has been released under a CD:
HOBO JACK TURNER Ernest Hare 20-cut BACM CD 1928-1932
Sorry Adam but you aren't related to Bob Miller