His victims start quarreling and ultimately fighting each other while speaking in green-colored speech bubbles, which symbolize darnel.
From the en.wikipedia.org
It protects against an array of common weeds such as wild oats, green and yellow foxtail, Persian darnel, barnyardgrass, and volunteer barley, oats, wheat and canaryseed.
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Weedy annual grass often occurs in grainfields and other cultivated land; seeds sometimes considered poisonous
Lolium temulentum, typically known as darnel or cockle, is an annual plant that forms part of the Poaceae family and part of the Lolium genus. The plant stem can grow up to 1 meter tall, with inflorescence in the ears and purple grain. It grows plentifully in Syria and Israel.