I agree with you Millet. This might be a cross of mandarine. The ones commonly grown in that area are Chahara and Zorana. Both are Satsuma, hardy mandarins.

Sylvain,
If it can be of any help, here is an extended list of mandarines used in plantages,
Early rippening: Chahara, Okitsu, Miho, Kawano Wase
represents ~70% of all mandarine trees.
Late rippening: Kuno, Unshiu, Owari, Saigon, Clementine

I don't know the year of introduction of specific variety.

Zorica Rana as the variety is younger than the lemon trees in the question.

More information:
"The past and the present of Citrus Certification in Croatia"
http://ressources.ciheam.org/om/pdf/b43/00800068.pdf
Read the section "Sanitary status of Croatian Citrus" for early history.

Ivica, your link is very interesting. I learned something today. I was unaware of a citrus industry in Croatia, and lemons on the Island of Vis. I visited the Island of Vis via Google Earth, but was unable to spot any lemon groves. Thanks for the link. I enjoyed it. - Millet (1,145-)

Millet,
Lemon production in Croatia is 2.700 tones per year, Vis island with 7.000 trees produces 250-300 tones. Those lemons are not chemicaly treated, climate conditions are close to ideal, fruit quality is superior.
However, none bothers coming there and buying up their production and people are discouraged to grow them, lemons left to rotten in a storage or even unharvested left to rotten under the trees is not unusual there. Absurdly, even in an island store one can find imported lemons and of suspicious quality.

Fields are usualy small, experimental grove of 2.000 square meters should be near Komizha...
http://static.panoramio.com/photos/original/26625044.jpg
http://static.panoramio.com/photos/original/25955534.jpg

I know nothing about varietes grown there, things to do...

Off topic but this photo of a lemon tree on Vis island is amazing,
growing through the window of abandoned house:
http://kut-.bloger.hr/post/limun-na-prozoru/371144.aspx

A few photos from that perfect place for retired citruholic, just a dream...
Photo Galery:
http://www.otokvis.net/index.php/foto-galerija/
Photo Forum:
http://otokvis.info/forum/index.php?board=4.0
Video Forum:
http://otokvis.info/forum/index.php?board=18.0

do you have any rooted cuttings for sale of the lemon.artie

artie10,
No, not yet.
Research of this lemon is still in its very begining.
Plus, a lot of other things are missing:
infrastructure (nursery, greenhouse, the lemon foundation block...)
papirology (fito certificate...)
...
It's a long run.

Seeds seems to be of 2 type, Regular and Green.
Photo showing seeds from older and younger fruit:



Seeds cuts:



Green seeds can not wait as long as the tree can hold fruit:



3 the most impatient green seeds are planted now.
I have 2 remnant seedlings from the summer test of the viability of seeds found in 3 year old fruit.
Maybe comparing seedlings can reveal some new information.

Lemon graft has been chalenged by Cold Wave last week.
Report is here:
link

Ivica, I should also mention that mandarin seed are not the only possible green citrus seeds. Seeds of over ripe fruit can also become green in color, and sometimes even sprout while they are still in the fruit. - Millet (1,120-)

Millet, thank you for information.
Even if mandarin is in background of this lemon that do not give us all answers.
We still don't know what should/could be responsible for exceptional fruit keeping characteristic of that lemon tree.

Loud thinking here, maybe varietes as Citron (Citrus Medica) and Pomelo (Citrus maxima) could be also part of this equation. Those can be found in south backyards and locals have names for them, Chetrun and Chadek.

Discussion about possibilities of hybridization is here:
link

The regular seeds look like normal lemon seeds, the 'decline' are seed that grew without fully developed embryos, and never progressed any further. These are the type usually floated off before planting the plump ones.
The 'green' are seed that have begun to sprout inside the fruit, which is fairly common when fruit is stored too long on the tree. I dont think that these green cotyledons point to any mandarin ancestry, as you would expect it at the early stages of seed development, before they seem to be sprouting.

pagnr,
thank you for participating in discussion.

pagnr wrote:

... The 'green' are seed that have begun to sprout inside the fruit, which is fairly common when fruit is stored too long on the tree...

That is what makes the observation "weird", i.e.
"fruit is stored too long on the tree" translates here to a year old fruit.

What to think about fruits hanging on the tree for 2 years, and more ?

Answering ilyaC question (Posted: Wed Mar 10, 2010 3:27 pm at
link
"How many months does it take for your lemon to mature from flowering?"

I allowed my brain to follow weird paths and have said:
"... Could be something similar to standard lemons, 9-15 monts.
What happens inside the fruits after that is beyond me...
One difference is noted already, so far I saw Green seeds in young (a year) fruits only.

Loud and weird thinking follows, what if those fruits have two rippen stages:
Normal stage: Over-rippening means -> Green seeds sprouts and decline.
Exceptional stage: Over-rippening means -> fruit decline.
"

The trees are in their winter position since mid December:

Only one sheet of plastic but that is not so bad as it could look. House walls plus door on that side helps a lot.

The trees are ever-blooming.
Whenever I was there I was able to find flower buds as well as fruitlets, summer/winter dormancy periods included.
Photo 2009-12-23:


Photo 2010-03-14 #1:


Photo 2010-03-14 #2:


Lot of dust on leaves, they do need good rain/shower.
The trees were out since early March last year, this year that will be late March, probably. Winter was extreme one.

Can anyone comment on it, please:
"Gene controlling life span of leaves in plants and method for controlling life span of plants using the gene"
http://www.freepatentsonline.com/y2005/0055745.html

http://www.freepatentsonline.com/20050055745.pdf

Above applies to citrus fruit tree by claim 12.

I wonder could similar gene be explanation for observed (by mother trees owner) longevity of fruits.
Abscission leaf experiment is ongoing, abscission fruit experiment follow when lemon graft become productive.

Helpfull links/terminology:
"Longevity" http://en.wikipedia.org/wiki/Longevity
"Plant senescence" http://en.wikipedia.org/wiki/Plant_senescence
"Abscission" http://en.wikipedia.org/wiki/Abscission
"Marcescence" http://en.wikipedia.org/wiki/Marcescence