Slc. Orpetti opened, and flower looks very different
 

I have posted two pictures. One (img 2758a) from last year's bloom cycle, and the one I took today (img 3605). What could cause these kinds of variations from one year to the next? I hope I haven't doomed my plant. I am stumped...and still have loads to learn. :(
Thank you :bowing

The heat, too much/little sunlight, pH, and nutrient balance can all affect blooms. My Burr. isn't nearly as red this time as it was in the winter when light and heat were more suitable.

Thanks...Having flashback to last summer. We had a heat wave down here. 90 days straight above 100 F, some peaking out ~115 F. That may explain it. Even inside the greenhouse with the chiller running full blast, it was tough to stay cool. Although it did stay significantly cooler than the blast furnace conditions outside. The gh topped out at ~ 90 on the really hot days. :hmm I wonder if the heat was/is the culprit. The plant hangs from a rafter near the chiller, so it's at the top of the gh. I have fans running in there 24/7 through the summer.

I have been using the MSU fert for several years now with great overall results. Are there other micro nutrients that I need to be conscious of?

I find this very unusual, the flower petals etc can alter but not the lip markings. Its almost like a second plant is flowering.
It was a Sophrolaelia, now Cattleya. The parents are C. (L) pumila x C.(S) coccinea.

Are you sure that there are not two different plants here? There can be differences in color and shape from year to year, but I agree that the lip cannot alter this much.

As far as I know, it's the same plant growing on the same mount.... good grief. I'll check my records to be sure.

well the flower from last year manifested the pumila form and colors....this year the flower showed the coccinea's inner lip colors....I think there are two variant plants in the mount that grew together since seedlings....as the mount produces more bulbs you will distinguish which is which when they both bloom at the same time

I never thought of two different siblings but I have to agree that this is likely your answer. Sometimes when I repot new seedling orchids, I find more than one in the pot and separate them. How nice! Two different siblings!

Eating a serving of crow....
 

I went back and realized last year's photo was of Slc. Trudy and Red Marsh.... this year is the first blooming of Sl Orpetii. Will I be stripped of my OB membership, now? I am feeling like a real bone head.... For those of you that noticed, thanks for pointing it out to me. And thanks for any replies to this. Proof that OB has good-hearted members (especially when dealing with those of us who arrived on the short bus) :blushing: :rofl:

Mystery solved! :)