This plant made a vigorous new growth this year but there is no sheath. Based on my post last year, it looks as if this plant blooms from a sheath.

Does this just sometimes happen? Or is it probably not getting enough light (I thought it did).

You might check the leaf color. If the new leaf is darker than the old ones, you probably aren't giving it enough light. Is the Pseudobulb at least as big as the one that bloomed? If not, you might want to look at other cultural variables. Also, a sheathless pseudobulb will occasionally produce a bloom.
I hope this helps.

Oh! That color! Like sunrise on a spring morning. Thanks for sharing.

The new bulb is larger than all the rest, by a good 20-33% I'd say; and if anything the color is lighter than the older ones! So I'm stumped. Guess I'll just wait and see.

I haven't seen it written anywhere, but I do kind of wonder if some plants, some years, just take a break from flowering. I suppose there'd be no way to truly test this; but the opposite corollary is that given ideal conditions, every plant will bloom every year. Any botanists among us? (I admit, I'd like to think that I am right, because it excuses my less than stellar results with some plants!)

Yes, I have seen Cattleyas bloom on every other pseudobulb. I also have one that produced two pseudobulbs one year. One had a sheath, the other didn't. The sheathless growth was the one that bloomed. Go figure. :dunno:
So there is hope.:goodluck:

Exactly what I wanted to hear! I had a feeling this orchid thing didn't make sense :)

Rhyncattleanthe Hunabu Victory
 

The plant appears to have buds from the new growth, without any sheath! Currently extremely small, not really worth a photo yet.

I looked this up on Blue Nanta, I bought it labelled Blc. Apparently that was incorrect, it is Rhyncattleanthe: Rhyncholaelia x Cattleya x Guarianthe, which is abbreviated Rth. It is a cross of an Rlc and an Rth -

Rth. Hunabu Victory on Blue Nanta.

You'd think that would make it Potinara? But I guess only four specific genera make a Potinara

(Why is my potinara not a potinara), Manatee Orchid Society