American Barleywine is a more assertive, hoppy, and complex version of an English Barleywine. Instead of the usual balanced malt and hop character, the American version is usually more aggressively hopped - although the flavor can range anywhere from sweet and fruity to pungent and pine needles.
The color is generally somewhere between amber and a reddish copper or even light brown. Malts are generally sweeter caramel malts, while the hops are abundant and evoke a fruity or citrus flavor. ABV is generally fairly high (8% or higher), as is the bitterness from the hops. Intense is the best way to describe beers of this style.
Usually best served warm, around 50-61 degrees, and in a beer snifter, a stemmed tulip glass, or even a large wine glass. Most barleywine is bottle-conditioned, and can be stored and cellar aged much like wine.