4/14: remembering

...a good thing from yesterday:  I saw an iris bloom iridesce, its petals sparkling in the sun.

And a good thing from today:  I learned that the word iridesce is a back-formation.  Once I typed it here, I decided to look it up, and the OED identifies it as a 19th century back-formation of the 18th century iridescent.  (It's hard to identify back-formations, so it's always a pleasure when I find one.)