Definition of Festuca
In Frankish law, a rod or staff or (as described by other writers) a stick, on which imprecatory runs were cut, which was used as a gage or pledge of good faith by a party to a contract, or for symbolic delivery in the conveyance or quit-claim of land, before a court of law, anterior to the introduction of written documents by the Romans.
That's the definition of Festuca in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.