Open one up, you can tell a Meyer from the inside. Though it definitely does look like a Meyer based on its orange yellow color.

I’ll post a photo of the inside tomorrow. Thanks!

Taste it! Do you know what a Meyer tastes like?

Those sure look like Meyer lemons to me. If you scratch the rind, it should have a fragrance that smells more like a blend of lemon and tangerine than the more common grocery store lemons. They should be juicier and sweeter than regular lemons as well - tho still sour.

The ones I used to grow had thin, soft skins, a golden color and a rounder form.

Unfortunately I don’t know what a Meyer lemon should taste like. I scratched the rind and I think the odor is vaguely reminiscent of tangerines. I’m attaching a photo of one cut in half with a Harbor Freight yellow & Corn chip orange for comparison. Any advice concerning care/fertilization/pruning would also be appreciated. The tree has some thorns, by the way.

I agree!

Yes, certainly looks like a Meyer's Lemon, were they more yellow a few weeks ago? One good thing about Meyers is that they keep on the tree for much longer than most other Lemons and will produce more than one crop per year, which is handy when you have an in ground tree. As to fertilizer, unless you are wanting to try to maximize growth / production a cheap balanced yard fertilizer used sparingly will work ok. Given the size of the tree I would suspect you need 6 or so pounds per year of 8-8-8 or 13-13-13 lawn fertilizer, applied a pound or two every month or two between February and August. This is not optimal, but should work ok, depending on local soil conditions, a fertilizer with micro-nutrients would be better. This assumes that you are happy with the current size, for optimal growth you would need more fertilizer. Given your location in FL, you might be about to buy 50 pound sacks of citrus fertilizer from a local fertilizer suppliers. I buy Citrus fertilizer in 50 pound sacks here in Louisiana which I think is an 18-9-11 commercial citrus blend for around $12 per sack. Correction the blend I use is a 14-4-9 citrus blend with micros, last time I bought it the price was $9.80 for 50 pounds. The 18-9-11 is what I use on my other non citrus fruit trees.

Thank you, Ike, for the advice on fertilization. Do I ever need to prune it or just let it grow?

There is rarely any need to prune citrus, though you might want to if the limbs start sagging and touching the ground when they are loaded with fruit.

I believe it's also a good idea to prune any limbs that rub against each other.

Perhaps, but my feelings are generally let citrus be citrus, way too many people try to apply general deciduous fruit tree pruning rules to citrus, which is a very bad idea. Citrus is a closed canopy tree, not an open canopy, also citrus wood is far more flexible and will handle far more weight than the wood of common fruit trees. So unless you have an out of control limb in your way, or one drooping to the ground don't touch it, also you DO NOT need to thin the fruit on in ground citrus, it will tend to shed any fruit it can't support. If it does not succumb to Citrus Greening disease, which is rampant in Florida and has no treatment, all it needs is a bit of fertilizer and maybe water in the unlikely event of a severe drought.

Our lovely lemon tree seems to be suffering this year. I’m not sure whether it’s disease, lack of fertilizer (I thought Mike had done it & he thought I had), the hot dry summer we’ve had. Any suggestions? Thanks for your help.

Looks under nourished. Citrus are heavy feeders. A tree the sized of yours should be fertilized 3 times per season, equally spaced our.

Silica, thank you!

You might be in HLB country. If your plant got that, then there's not much hope. I don't want to be the bearer of bad news, but it's a possibility.

What is HLB please and how is it spread?

Hang Long Bing disease. It is a bacterial disease that attacks all citurs trees and kills them in a very short period of time. It is spread by the Asian Citrus fasilid.