PM was not working for me--here is my reply to your PM:

I have a Lisbon lemon. I think it and Eureka are considered true lemons. I believe Ponderosa is as well but it is large, I do not know about Sambo.
Meyer is a hybrid (grapefruit and something) but it has a lemon flavor when it is just turning from green to yellow and I have heard it is more cold hardy.

My tree is on the NE corner of the house (it would be better for cold protection on the South side), but the brick does retain some heat. For protection in the Jan mid 20s, I had it wrapped to the roof line with several layers, a kiddie pool full of water under it, and 2 strands of Christmas lights around the bottom. The part above the roof line (unwrapped) was defoliated but is putting out new growth now. I think it would have survived upper teens with out much damage. I have over a dozen varieties grafted onto the lemon and all made it without damage --including oranges, grapefruit, mandarins.

Ponderosa is not a true lemon and either is Sanbokan.

The lemon itself is a hybrid between sour orange and a citron, and the sour orange is a hybrid of pummelo and mandarin.

So what's the definition of a true lemon?

Some lemons considered true are:

Eureka
Lisbon
Harvey
Bearss

These are the most common in the USA. There are quite a few other Italian varieties that are also considered true.

I have a Bearss lemon that has made it through several freezes over the past 8 years. The top new growth had some damage this past January but the lower new growth looks fine. Last year I had quite a few fruits around a pound each.

My Meyer lemon (same age) growing right next to the Bearss had no cold damage this year. Both are loaded with flower buds.

Bearss lemon?? Is that AKA Bearss Lime??? or are they different?

Joe, interesting note on the origin of the lemon! I didn't know that.
Greg

Greg have a look here. http://www.hort.purdue.edu/newcrop/morton/lemon.html

Quote:

'Bearss' ('Sicily', but not the original introduction by Gen. Sanford in 1875, which has disappeared)–a seedling believed to have been planted in 1892, discovered in the Bearss grove near Lutz, Florida, about 1952. Closely resembles 'Lisbon'. It is highly susceptible to scab and greasy spot and oil spotting. The tree is vigorous and tends to produce too many water sprouts. Nevertheless, it has been propagated commercially by Libby, McNeill & Libby since 1953 because the peel is rich in oil. It constitutes 20% of Brazil's lemon/lime crop. ,

Laaz,

Is that ever right about water sprouts! Loads of them. I have been pruning the tree lately, still need to cut off a few sprouts.

tolumnia yes mine has many sprouts, but they all produce fruit in time. You know I forgot all about my Bearss lemon all winter. It never had any protection & saw a low of 24 F in a 20 gal pot on my back deck. I just went out and checked & it is flushing & budding out. Lost some leaves, but looks to be in great shape with no dead wood. May have to put this one in the ground this year. I'll get some pics this weekend.

My problem is that the remaining sprouts are so tall that they are shading other trees too much. The tops of the tall sprouts were killed back about three feet in the last freeze, but the lower branches are fine. Also, way too tall to easily harvest any fruit.