The last photo definitely doesn't look like a native azalea. I would hesitate to speculate what it is.

The distorted leaves are probably caused by gall midge leafhopper injury, chemical injury, leaf-roller activity or aphids.

Young leaves rolled and distorted could be either chemical damage or Rhododendron Gall Midge, Clinodiplosis rhododendri. Chemical damage should be associated with a chemical application (fertilizer, herbicide, deicing salt, etc.) and should affect more than one plant. The Rhododendron Gall Midge is a native pest of Rhododendron catawbiense, R. maximum and their many hybrids during the May to October growing season. The larval feeding damage from this fly can cause discoloration and distorted foliage. This damage can appear as in-rolled, twisted leaves that have turned a yellow color. This can be seen on young leaves that have separated from the bud scale. Leaves attacked in the bud stage may die if the injury is severe. Care must be taken to distinguish this pest damage from similarly manifested damage caused by leafhopper injury, chemical injury, leaf-roller activity and aphid feeding. There is no way to undo the damage once it has occurred. Control is effected by applications of insecticides with the bud break stage of rhododendron development. An alternative would be to maintain healthy plants so that they could survive any damage caused by an infestation or to prune newly-infested foliage that contain larvae.

Distorted young leaves covered with Aphids can be a problem in the spring. These small sucking insects feed on the new growth as it begins to expand causing distorted leaf shapes. In large number, their sucking damage causes new leaves to twist and curl. A secondary problem is aphids excrete a sugar solution called "honeydew"Âa perfect food source for the sooty mould fungus which grows on the honeydew causing plant leaves to look like they are covered in black soot. The fungus isnÂt actually parasitizing plant tissue, but it coats the leaves to such an extent that plants canÂt photosynthesize efficiently. In time, natural predators will help. The most famous is the ladybug, whose larval stages eat quantities of aphids. There are other predators, too. As a last resort, insecticides are available. The aphids can be controlled with Orthene, Malathion or Diazinon.

Here is a link that might be useful: How to grow azaleas and their problems.

Thanks, Rhodyman. I'm quite sure the diseased one is not suffering chemical damage -- I've done that and learned better. Only rain water near these (added some home-made compost to the nursery bed to raise it, but anything in it should have affected all plants). But I have also not seen any insects on the plant, certainly no aphids. I'll keep an eye out for them though, probably next year, since we're due for a frost sometime soon (or at least usually are, been pretty warm).

That unusual, smooth-leaved one grew from seed labeled R. calendulaceum I got from the New England Wild Flower society. Maybe I'll ask them whether that seed was from their own plants and whether it might have been contaminated by something like this, or whether this is something they recognize.

Thanks again.

I've had a suggestion that the last seedling was a Rhododendron carolinianum. Any thoughts?

Yes, the last one looks about right for Rhododendron carolinianum. Looks a bit too smooth to be Rhododendron minus, has red petoles, evergreen... Check the underside of the leaf... brown spots? scales? any scent from the leaves?

If so, a very pretty plant to have, and quite cold hardy.

Thanks, sandyhill. That's what I thought, too. The plant is at my house upstate, so I'll only see it this week-end to check for the scales on the underside. If they are there, I'll assume that's it. The leaves have a reddish tinge that most pictures of carolinianum I've seen don't have, so I'm not completely positive, but that may just be individual variation.

The New England Wild Flower Society was also selling R. carolinianum seed at the same time I got some R. calendulaceum seed from them, so a seed from carolinianum probably just got mixed in by accident.

Actually, the link below has a lovely picture of a specimen with leaf shape and color similar to mine.

Here is a link that might be useful: Carolina Rhododendron in the Wild

Rhododendron minus var minus (formerly called carolinianum) is a lepidote rhododendron. Many young lepidote rhododendrons and other species (not rhododendrons) look like those leaves. You would need a flower to confirm the speculation. What we do know is that it is not R. cumberlandense or any other deciduous azalea.

You are perhaps correct in theory, rhodyman, but consider the source of the seeds, which I noted above. I got them from the New England Wild Flower Society's native seed sale, among some calendulaceum seeds, and carolinianum was the only lepidote rhododendron whose seeds they were selling at that time. While it's possible that a seed from some other lepidote rhododendron wandered into my calendulaceum packet, it seems pretty unlikely to me. (I'm not aware that NEWFS grows any other lepidote variety except R. groenlandicum, which their nursery sells, and I don't think this is that.)

Until you see the flower you can't be sure. There is not one characteristic of those leaves that limits it to the genus rhododendron. Many members of the plant kingdom look like that at that stage. All we know for sure is that it isn't a deciduous azalea. I would venture to say that it is a broad leaved evergreen of some kind, and beyond that it could possibly be R. minus as well as a huge number of other things.