My regular white ones are back, but I've noticed a little stand deep in the woods is down to a few bloomers where in years past there were many more. There are lots of little trillium youngsters in that area instead. Otherwise a normal year here.

One bonus: I was lamenting that I paid some hideous amount of money (You've prompted me to research a little more about these woodland lovelies and if I find anything that would answer your question, I'll post.

Means not old enough or not doing well enough to flower, same as with other bulbs.

My late mother loved Trilliums and had them growing in the wooded area around our farm. I stand to be corrected but the flowers are never to be picked or they don't bloom for seven (7) years???? Good Luck

The problem would be taking the foliage away with the flower. If you just picked the flower, the plant wouldn't care--in fact it would give it a little more energy for growth because it would have been deadheaded--but who's just going to pick the flower off the top, leave the rest?

7 years has been given as a typical wait from germination to flowering of trillium seedlings, maybe the supposed effect of picking the flowers (and foliage) has been confused with this. Or, taking the foliage knocks the rootstock back so far it almost has to start over--although I doubt it, myself.