What's up with this Angcm. leonis leaf??
 

I didn't capture it as well as I'd have liked, but the new leaf on my leonis is mottled and pale green, then almost white in places. compared to the previous leaves, it looks unhealthy. It doesn't look like the more yellow leaves you see when one of these gets a lot of light. those are pretty uniform in color. Anyone have an idea what's going on here?

I haven't seen anything like that with my leonises. I hope someone can help you.

Thank you, Leafmite :)

Okay, I gave this a little thought. I honestly cannot say what is causing this but here are a few ideas:
1) nutrition deficiency/imbalance/toxicity. It might be missing iron or magnesium or something odd. I saw this when I forgot to fertilize or when the plant isn't getting the right balance (a few of my plants have special needs)
2) pH. Some of my low pH plants have gotten this and upon lowering pH, the new leaves are green.
3) too cold?
4) too wet?
5) fungus?
6) too little light (believe or not, with some of my plants that suffer from too little light, the leaves don't yellow evenly)
7) scale or mealies getting in between the leaves. I got rid of them but I had both hiding in one of my leonis. The leaves apparently are folded together and make a perfect shelter.
8) cold water or some aerosol getting on the leaves
9) not likely but rarely, this is caused by virus. I don't think this is the case, to be honest.
These are all the factors I can think that might cause this.
I don't know how helpful this list is. :o
Hope it isn't anything serious. Mine are currently recovering from my attempt to grow them in lava rock like most of my other angraecums. I switched to sphagnum moss and small net pots which seems to please them. Since you are one of the few that also seem fond of the angs, I am really anxious for yours to make a full recovery. I just added an elephantinum. :)

Appreciate your thoughtful reply. I've got two of these madagascar leonis purchased at the same time, and the new leaf on the other one is similarly off, though not as dramatically. I'm sincerely hoping it's in the conditions, and not viral. They are in coconut, charcoal, sponge rock and tree fern, with a layer of moss recently added to help retain moisture.
PH is a possibility. It's not something I've monitored, or know how to.
Temperature: little variance from day to night. Between 70 and 73.
Too wet: the mix is quick drying and I saw some dehydration in the leaves recently, thus the moss. don't know how to know for sure without tipping them out of their pots.
Light: they've been under light sufficient for my little Dens. Maybe too much.
Fungus: my ignorance is complete on this one.
Scale, mealies: not in evidence. Hiding well if present.
Water on the leaves is possible, if room temp is too cold.
They've been fertilized regularly with Jack's classic at a low concentration and occasionally with Solo--MSU fert + seaweed xtract.
I looked high and low for the madagascar var. of leonis, so I have a lot invested in these guys. Really hope this is a hiccup and not dire.
I do really like the Angs and wish there were more of the smaller ones available where I am. Aloifolium is one I'd particularly like to grow.
I've got praestans and rutenbergianium growing well for me, though haven't yet had my first ang bloom.

I'd love to see your new one and your leonis, in or out of flower!

If I had a greenhouse and a vast fortune, I would probably (ha, definitely!) seek out the 200+ species. Unfortunately, I have pretty much filled my windows and not much light gets past the plants/orchids in wintertime so I am not actively seeking to buy more orchids or plants. If I see one at a show, however....
I tend to buy seedlings and wait years for blooms. Ihave didieri (3), elephantinum, a magdalenae, the leonises (2-I don't know which type), sesquipidale, and distichum. When the didieri bloomed (my first ang bloom), we had hail the next day, before I had a chance to take a picture but I plan to post pictures of my babies' blooms in the future. :)
In the summer, I put a handful of Ironite on the bottom of my watering can and when I water, I add a little Epsom salts and a little powdered milk (yeah, weird), then add the MSU fertilizer. I use red lava rock or mounts (bare) for most of my orchids and the fertilizers are formulated for bark or moss. With the rapid growth, my orchids needed the extra boost. Here are two sites:
Orchid Pests, Orchid Diseases
http://www.houstonorchidsociety.org/...ySueBottom.pdf

Here are the pictures. The mounted one is the new elephantinum, the one in lava rocks will be my magdalenae (the one that started it all) and ones in moss are the two leonis. The smaller one has some ways to recover after the scale and mealie infestation but it survived and both have just 'enjoyed' a dryer winter rest. I threw in the mag because it has the nicest leaves. :)

I believe it's nutritional.

How much of the two products are you applying, and how often?

I don't know the particular Jack's formula, but the Solo should be applied at a tablespoon per gallon approximately every two weeks and the pot should be saturated when you do.

I'm going to echo Ray. I was having a lot of problems with yellowing leaves on Masdevallias (I grow in sphagnum also) until I read the article in the new issue of orchids and started using a lower Potassium and higher Calcium and Magnesium fertilizer (Ray's K-Lite). The change was dramatic. The plants greened up and are doing much better in just a few weeks.

Thanks to all three of you for the feedback and to Leafmite for posting your Ang. photos. You have great plants!

I use Solo in RO approx. monthly at 1T per gallon. Jack's is a 7-5-6 with micronutrients formula that I usually use at all waterings, except when using Solo. I use 1/2 tsp of Jack's per gallon of RO, as recommended for use at each watering. This Jan and most of Feb, however, I didn't use either, only watered with RO.