there! i knew nohrnberg knows everything! i asked him about my list of flowers and he wrote back immediately:

"Lily Pons (when I was very young) sang Mimi in La Boheme, but the ref. is probably to the latter being a seamtress who takes pleasure in embroideries of lilies -- and roses. Carmen throws a seductive red flower from her bodice at Jose, at the start of the tragic action, and carmen is a shade of red. The exile Aida sings O Patria Mia upon emerging from an Egyptian palm grove (palms are the chief Egyptian tree -- see Phoenix and Turtle, 1st stanza). Gounod's opera's Faust has an ineffectual rival in love-smitten Seibel, who hangs a bouquet of somewhat disregarded flowers on Marguerite's door at opening of Act III; he's picked them from the garden at the back of her house."

so now i have a complete set of references to the 11 flower riddles on my scarf.