Lemon & Citron
"Names for lemon in a large number of European tongues derive from Latin citrus, e.g., German Zitrone, French citron, Finnish sitruuna, Latvian citrons, Czech citrón, Polish cytryna, Hungarian citrom, Yiddish zitstrin [זיצטרין] and Armenian gidron [կիտրոն], all of which mean lemon.
Some languages have similar names for the more ancient fruit, citron, which should not be confused with lemon: Croatian četrun, Polish cytron, French cédrat, Italian cedro, Russian tsedrat [цедрат] and Greek kitro [κίτρο]."
http://research.fuseink.com/cp/MTAwMzEwNg
http://www.uni-graz.at/~katzer/engl/Citr_aur.html

My note:
People in some areas of Adriatic call citron simply "wild lemon",
in some areas asking for četrun you could get (water)melon.

Cedruna
"This very old variety is thought to have originated in India, whence it spread to Persia and circa 300 B.C. to the Near East. It arrived in Europe via Sicily and Sardinia after 200 B.C. It used to be widely grown in Calabria and Campania and to a certain extent on the islands of the Dalmatian coast and Ionian Sea. Recently its growing area has diminished. "
http://users.kymp.net/citruspages/citrons.html#cedruna


Source: http://www.safiresabzejahrom.com/

Cold hardiness?
Citrons are very tender wrt cold, also I have read somewhere, can't recall the source, that citron do not like just too cold but also too hot environment.

How large can fruit be?
How long can the tree keep a fruit?

If you have more photos or information, please, post them here.

There's more confusion in citrus name-giving...

Where I live (Belgium/Flanders), we talk about "pomelo" (citrus maxima) and "pompelmoes" (citrus paradisi, grapefruit).

In French these names are also used, but reversed: they talk about "pamplemousse" (citrus maxima) and "pomelo" (citrus paradisi, grapefruit).

Here is something what have captured my attention recently:



Not Cedruna but according to this news article
http://www.jutarnji.hr/kod-benediktinki-rastu-limuni-od-1-3-kilograma/209743/
autochthonous domestic variety (a četrun). Mother tree is in Benedictine monastery in Trogir, Croatia.
Thanks to the Benedictine nuns of Zadar, trees grown from the twigs of their pet ended up in many gardens in Zadar, as well as in monasteries in Italy.
Maybe unusual characteristic for citron, article says fruit (weight up to 1.3 kg) can give up to 0.9 litre of juice.
Looks like one more item asking further research.

Citrons are very variable, generally considerably larger than lemons.
I recently posted photos of two varieties that are currently fruiting in my greenhouse.
See topic
link

Mike/Citrange

MarcV, local name for Citrus grandis (maxima) on Adriatic islands is čadek.

Mike, please post photos of fruits halves when that become possible.

Četrun tree on island of Vis, Croatia:


More photos here: http://palmapedia.com/index.php/topic,348.60.html

Fruit keeping is the characteristic of my main interest:
"The citron does not fall off the tree and can reach 8–10 pounds (4–5 kg) if not picked before fully mature.[7]"
http://en.wikipedia.org/wiki/Citron

Četrun fruits on island of Lošinj can remain attached to the tree up to 3 years. That location deserves own topic which I'll open later.

Thanks Ivica. Here is the English version.



http://translate.google.com/translate?sl=hr&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.jutarnji.hr%2Fkod-benediktinki-rastu-limuni-od-1-3-kilograma%2F209743%2F

Thanks very much for this enjoyable thread! Is there any chance of sourcing a young tree of each of those citron varieties to buy?

Thanks Ivica. That's a shame they aren't available. They sound like very nice varieties to have, especially for making hybrids.

Ivica, here is huge info about citrus medica in mediterranean area, in czech language, written by Peter Broza http://www.citrusy.cz/forum/viewtopic.php?f=2&t=1645&st=0&sk=t&sd=a&hilit=citrus+medica&start=150
He also has citrus medica "cedruna" in his collection.
Pure citrus medica (because here are a lot of hybrids, which are less cold sensitive) is extremly cold sensitive citrus. Even in Italy they grow it under protections against cold in Santa Maria del Cedro region, which is the famoust cedrat growers region in Italy.

Mike, thank you for the photos.
Radoslav, thank you for the link, really a lot of info there.