It was grown in the Tuilieres Garden during the Paris Commune to stave off starvation, and it was planted to feed families after the shrinkage of farm plots in Ireland.  
This object is seen thumbing its nose at a German U-boat sailor in Mr. Punch's History of the Great War, in response to the US entering WWI, with the object saying it is "über alles" in its namesake "repartee".  In the late 18th century, Marie Antoinette was given flowers associated with this object as part of a publicity campaign by Parmentier, who also kept this crop (*) guarded by soldiers who were told to accept bribes, so that it would appear valuable and peasants could steal them.  It was grown in the Tuilieres Garden during the Paris Commune to stave off starvation, and it was planted to feed families after the shrinkage of farm plots in Ireland.  Introduced to Europe from the new world, for 10 points, name this starchy vegetable whose famine in the 1840s led to a massive emigration to North America.
This object is seen thumbing its nose at a German U-boat sailor in Mr. Punch's History of the Great War, in response to the US entering WWI, with the object saying it is "über alles" in its namesake "repartee".  
{potato} (accept “tuber” in the first sentence; prompt on that answer afterwards)