Potato

"These are potatoes, Comrade Commisar! Why are we using potatoes instead of real grenades?" "Because real grenades are valuable! In fact, they are worth a lot more than you are!"

- A Russian soldier and Commisar Letlev

The potato is a starchy tuberous crop from the plant Solarum tuberosum of the Solanaceae, or Nightshade family. It is the worlds fourth most popular crop--following rice, wheat and maize (corn). It is originally believed to have evolved in an area of southern Peru, spreading and diversifying into thousands of varieties, up to a 100 sometimes growing in a single valley. Used for thousands of years by native peoples, the Potato was first found by Spanish explorers in the 1500's. It was later exported to Europe, the Americas and throughout the world. It became especially popular in areas where the soil was not rich enough for more traditional crops, such as Russia and Ireland. Today, however, Asia leads the market in potato production, with China the worlds leading exporter of Potatoes, followed by India. Products such as Potato Chips, French Fries and mashed potatoes all come from the potato. When fermented, Potatoes can be made into vodka.

In-Game
Potatoes are used in Red Army Training, the opening level of Call of Duty 2. They are grenade substitutes used by the player to practice throwing grenades, and also a nod towards Russia's production shortages during the early part of the war. Being nothing more than a normal potato, it does not cause any damage, nor explode like more conventional ordinance. If thrown at another character, it will harmlessly bounce off.

If you throw a potato at a German soldier in the level Red Army Training, the German will be surprised and confused, and say "Kartoffeln?" which is German for 'potato.' Also, if you throw enough at the German a potato will get stuck in his head.