Jatropha curcas

The threat of these nuts lies in their delicious taste because who eats one will instinctively eat several others. Beyond a dozen nuts occur cramps in the legs. The tree grows only in the tropics.
A creature subjected to this poison must succeed on a DC 10 Constitution saving throw or have its speed reduced to 5 feet for 1d6 x 10 minutes. Additionally, the creature can't take the Dash action during this time.