Wild arugula is, as Chris Kurth of Siena Farms in Sudbury says, “a bit of a misnomer,” as he orders the seed from a catalog and grows it in rows right along with regular arugula and other greens. Still, he praises the “spicier” taste of this arugula, also called sylvetta, a now-widely-cultivated variety that resembles plants still found growing wild in Italy.