Grechetto, Biancame, Pignoletto and our future friend Maceratino). For the most part, when people refer to a grape as "Greco," they are referring to what is technically known as "Greco Bianco di Tufo," though there is also a Greco Nero and a Greco Bianco di Novara which I believe are related to Greco di Tufo, but I can't really find anything definitive to that effect. Somewhat surprisingly, Greco Nero is actually much more widely planted than the Greco Bianco varieties, covering more than 3,000 hectares to Greco Bianco's 1,000, despite the fact that I don't believe that I've ever seen a wine made from (or even explicitly containing) Greco Nero grapes.
Most people believe that the name Greco is used for these grapes because they ultimately can trace their ancestry back to Greece. The story goes that Greco (or its immediate ancestor) was brought to southern Italy via Greece about 2500 years ago. Some people believe that Greco could have been the wine used as the base of the famous "Falernian" wine, which was perhaps the most famous wine of the ancient world, but as mentioned in my post on Falanghina, pretty much every grape grown in southern Italy is purported by someone to have been the primary grape used in that mythical wine. It is notoriously difficult to match ancient descriptions of wines with modern grapes for a lot of really obvious reasons, and it's my suspicion that most of these comparisons are made either by wishful-thinking modern drinkers who are caught up in the grandeur of ancient Rome, or by marketers looking to cash in on those same starry-eyed drinkers (see also my post on Abbuoto for a discussion of the same issue regarding the ancient Roman wine of Cecubo).
But is the grape really called Greco because it is ultimately from Greece? Yes, "Greco" means Greek in Italian, but it doesn't necessarily follow that it's named that because the grape itself is of Greek origin. In a paper from 2009 in the American Journal of Enology and Viticulture (full citation below), the authors indicate that in the Middle Ages, the word greco was used as an adjective to describe wines that were high in alcohol, sweet, and particularly long-lived. This description could have been applied because the style of the wine was Greek, not because the grape itself was Greek. It's easy to how, over time, the grape used primarily in the production of a wine called Greco might itself eventually come to be called Greco too. Over still more time, people may have forgotten the original source for the name and invented the very plausible sounding Greek-origin story to account for it. I don't know if that explanation is true or not, but it makes at least as much sense to me as the Greek origin story, and as far as I know, there is no vine in Greece today that resembles Greco di Tufo, or that has been proven to be genetically related to it.
Greco di Tufo has been shown to be genetically identical to at least one other prominent(ish) southern Italian grape, though. The researchers in this study proved that Greco di Tufo was the very same grape as Asprinio, a grape that is cultivated mostly around the town of Aversa in Campania. Rather than being grown in rows on man-made trellises, as most grapes are, Asprinio vines are trained up local popular trees and then across wires that are tied between each tree (you can see a picture and read a bit more about the process here). The vines can be quite high, and harvest often requires the use of a ladder for the picker. The wines are often made in a slightly spritzy style, though there are also still versions. I've only ever come across one bottle of Asprinio di Aversa, but it was sealed with a synthetic cork and had completely oxidized in the bottle (it was five years old and so probably past its prime anyway, but the cork failure rapidly accelerated this process and made the wine completely undrinkable). Asprinio and Greco Bianco are still listed as separate varieties by the Italian authorities (as in the case of Pigato, Favorita and Vermentino), but the DNA evidence pretty clearly indicates that they're the same thing.
Curtis Liquors for around $20. In the glass the wine was a fairly deep lemon gold color. The nose was reserved with some white pear and apple, but very little else. On the palate the wine was medium bodied with fairly high acid. It was very lemony with some flavors of pineapple and green apple as well, but with a bitter, pithy finish to it. The wine was tart, racy and lithe and was really a lot of fun to drink until the finish rolled around. This wine is a bit pricey for what you get, and there are a handful of other examples that retail for a few dollars less than this one, so if you're looking for a light, zippy, lemony white for summertime and come across one of those, give it a shot.
Muganu, M., Dangl, G., Aradhya, M., Frediani, M., Scossa, A., & Stover, E. 2009. Ampelographic and DNA characterization of local grapevine accessions of the Tuscia area (Latium, Italy). American Journal of Enology and Viticulture. 60(1): 110-115.