Verdelet and a painter named Grechetto. I've also learned that Grillo is the Italian word for cricket and that Trousseau is the name of a company that makes bridal gowns (that post was a two-fer as I also learned about a baseball pitcher named Bastardo, which is one of the synonyms for Trousseau). Today's Google image search on the Passerina grape was definitely the most colorful, though, as apparently Passerina is a bird genus within the Cardinal family. The North American Buntings belong to the Passerina genus and are quite colorful and vibrant to look at so if you're having a dreary kind of day, take a quick break to look at this page of birds and hopefully they'll brighten your day a bit.
Feel better? Good. The eagle-eyed among you may have noticed that around page 2 of the GIS, pictures of some plants start to show up that definitely aren't grapevines. There is also apparently a genus of plants called Passerina which you can read all about here. Believe it or not, there is a common link between the birds, the plants and the grape. In all three cases, the name Passerina comes from the Latin word Passerinus, which means "sparrow-like." This is pretty self-explanatory for the birds, as they do in fact resemble sparrows, though they are not related to them. The plants that belong to the Passerina genus have seeds that are curved and somewhat beak-like so their name comes from the fact that they're said to resemble sparrows' beaks. The grape Passerina is so named because it is apparently the snack of choice for the sparrows in the Marche region of Italy where it is grown.
Fascinating as all that may be, we're not interested in sparrows, buntings or weird plants here. We're interested in grapes and wines and the one we're interested in today is called Passerina. Passerina is grown exclusively in the Marche region on Italy's eastern coast. It's not a very common grape, but it does find its way into a few DOC wines like those of Offida (where it can be made into a dry table wine, a passito style dessert wine, a vin santo style dessert wine or a metodo classico sparkling wine) or of Falerio dei Colli Ascolani. It gets a cursory treatment in the Oxford Companion to Wine whose entry on it reads in full: "white variety from Italy's Adriatic coast." Wikipedia offers a little more, telling us that the vine has "large berries, high yields and a long ripening period" and that the grape makes "appealing wines with clear, focused fruit."
Once we move away from these two sources, Passerina becomes a bit more complicated. In his Brunello to Zibibbo, Nicolas Belfrage mentions that Passerina may be the same grape as Biancame and Bianchello, though he notes that his sources are not in unanimous agreement on the matter. The New York Times Wine Club website takes this position as well, but I can't find any other sources that agree. I checked the VIVC database but the information that they have only muddies the water. According to the VIVC, Passerina is a synonym for both Trebbiano di Toscana as well as Mostosa in Italy (with presumably the same etymological link to sparrows), though those grapes aren't grown in the Marche so they probably aren't what we're dealing with here. The only entry listed with Passerina as the prime cultivar name is for a Greek grape, and though this (admittedly non-academic and sales oriented) source posits a Greek origin for Passerina, they're the only ones who make that assertion so I'm taking it with a grain of salt. Since it doesn't look like anyone's done the DNA studies to prove or disprove the link between Passerina and Bianchello, the only option seems to be to note that the Italian government treats the two grapes as individual cultivars and follow suit.