Do you belong to iris talk? Since you are sick, but still computer worthy, you might enjoy the archives. It contains over 200 threads on the umbrata pattern. The term does appear to have been coined by Linda Mann to describe the 'shadow' fall pattern. My memory says there was some talk, also, discussing the appearance of the falls in bud. Could be I dreamed that part!
Didn't check the photo's archives.
KY Zone 6