Cr. 72/4 grain-ear/corn-ear series AR quinarius, 211-210 B.C., Sicilian mint
Roman Republic AR quinarius(15mm, 2.05g, 11h). Anonymous, wheat-ear/corn-ear series, ca. 211-210 B.C., Sicilian mint. Helmeted head of Roma right, V behind / The Dioscuri riding right, each holds a spear; wheat-ear/corn-ear below; in linear frame, ROMA. Crawford 72/4; Sydenham 194
Ex RBW Collection, Agora 73, 3/27/2018, lot 206, privately purchased from Dmitry Markov, 9/9/1994
This quinarius comes from the second grain-ear series, struck at a Second Punic War-era Sicilian mint referred to by Crawford as Sicily(2). Stylistic evidence suggest there were at least two separate Roman mints operating on Sicily at this time and you can see an example of the other mint's grain-ear quinarius here. These were relatively large and important mints during this era and both struck at least one issue of coins with a grain-ear mintmark. The repetition of the wheat-ear is not terribly surprising as Sicily was responsible for much of Rome's grain at the time and this symbol was a bold declaration of the importance of Roman control of the island. Later on as moneyers at Rome began to exercise more control over the designs of their coins the grain-ear symbol came back into use(as can be seen on this Minucia denarius), but since these coins were most likely struck at Rome, the grain-ear symbol was no longer a Sicilian mintmark but instead a political statement, generally interpreted along the lines of "My relative provided grain for you. Remember that next time you're at the polls."
I'll end with a quick note on terminology. Many websites and references refer to this mintmark as a "Corn-ear". This is not corn in the sense that many Americans think of it, but instead in British English, "corn" has a more generic meaning closer to the word "grain". I have chosen "grain-ear" here as I feel it is less ambiguous and matches my own understanding of the word "grain".