Phalaenopsis Leaf Morphology Change

[aliceinwl]

I have a few NOID mottled leafed Phals. They had very fat almost round leaves when I purchased them. The new leaves are thinner (in terms of width) and strap shaped. One of the plants also completely lost the mottling and the new leaves are bright green and shiny.

Is this due to lower light? Temperature? Humidity? The plants in question are in excellent health. But, I’m curious as to what environmental factors brought about the change.

[Ray]

If it's light related, and that's my bet, I'd guess it's getting more now than it had been - a long, narrow leaf has less surface area to gather light than does a wide, rounded one.

Mottled leaves suggest a fair amount of P. schilleriana in the background, and they are definitely hot growers, rarely seeing much below 70° in nature.

[aliceinwl]

Two of them have spent most of the year outside just coming into the garage at night when lows started getting below 50, but are kept fairly bright. The other one is inside in a fairly dark window. Dark enough that blooming is substandard for most of the Phals there. Seeing the same change in all of them is a bit puzzling.

Maybe I’ll play with moving them around and changing the lighting. Can mature unmottled leaves develop mottles in response to changes in light?