Cockle
COCKLE (בָּאְשָׁ֑ה, darnel [useless weed]). Only mentioned in Job 31:40, “let thorns grow instead of wheat, and foul weeds [cockle] instead of barley.”
The cockle is Agrostemma githago, and grows about three to four ft. high. The flowers are rose pink, and the green stalks have a gray down on them. It is a common weed of Palestinian barley fields. If the seeds are harvested with the grain, the flour produced can be irritantly poisonous. There ought to be, therefore, complete elimination of cockle plants when the barley is growing.
The actual meaning of the Heb. word is “stink”; some consider, therefore, that the tr. should be “noxious weeds.”
A similar word beushîm is used in Isaiah 5:2-4; Jeremiah 2:21; Ezekiel 15:2-6. See Dried Grapes.
International Standard Bible Encyclopedia (1915)
"Let thistles grow instead of wheat, and cockle instead of barley" (Job 31:40). On account of the meaning of the Hebrew root we should expect that the reference was rather to repulsive, offensive weeds than to the pretty corn cockle. It is very possible that no particular plant is here intended, though the common Palestinian "stinking" arums have been suggested by Hooker.