Hastings' Dictionary of the Bible (1898)
TARES, bearded darnel (Lolium temulentam), a grass sometimes found in our own grain-fields, but very common in Eastern countries. Matt 13:25. Until the head appears its resemblance to wheat is very close. The seed is noxious, even when ground with wheat in small quantities producing dizziness, and in larger proportions convulsions and death. Many instances of such pernicious effects are on record, some having been observed in England. Owing to its smaller size, the grain of tares is readily separated from wheat by winnowing.
Travellers describe the process of pulling up this grass and separating it from the genuine grain, Tares. and their descriptions perfectly accord with the language of our Saviour in the parable.