corn ((floor)), wheat

“Corn” From Boyd’s Bible Dictionary:

(kernel). In a Bible sense, grain of all kinds except our maize, or Indian corn. Used largely in figurative speech (Gen. 41:22; Ex. 9:32; Deut. 11:14; 18:4; 28:51; 2 Chron. 2:15; Isa. 28:25; Ezek. 27:17; Matt. 12:1).

“Wheat” From Boyd’s Bible Dictionary:

This well-known cereal was cultivated in the East from the earliest times
(Gen. 30:14), and grew luxuriantly and of many varieties in Egypt (Gen. 41:22). Syria and Palestine were both fine wheat-growing countries (Psa. 81:16; 147:14; Matt. 13:8). Wheat-harvest denoted a well-known season (Gen. 30:14).

“Corn” From Concise Bible Dictionary:

Various Hebrew words are translated “corn,” and usually signify any kind of grain. The “OLD CORN OF THE LAND” was what the Israelites began to eat after crossing the Jordan, when the manna ceased (Josh. 5:11-12). It typifies a heavenly Christ, on whom those feed who have spiritually passed through Jordan—who are experimentally dead and risen with Christ. The manna is rather heavenly grace for wilderness circumstances. In the New Testament Christ speaks of Himself as a “CORN OF WHEAT,” which had to die or it would abide alone: there could be no association in life with Christ except through death and resurrection (John 12:24).
Wheat growing in Israel.

“Wheat” From Concise Bible Dictionary:

Wheat Growing in Israel
This cereal was extensively grown in Palestine; the harvest was in May and June. In the parable it is used by the Lord as representing the children of the kingdom, the fruit of the good seed that He was sowing on the earth, in contrast to the tares, or darnel, which Satan secretly sowed among the good seed.
The Lord Himself, being the second Man “out of heaven,” is compared to the grain of wheat that must have remained alone unless it had died, but which in dying would bring forth much fruit. This clearly shows that there was no union of Christ and natural man by His incarnation alone, and that through the death of Christ the fruit produced by His resurrection is of the same order as Christ Himself (Matt. 13:25-30; John 12:24; 1 Cor. 15:48-49).
There are three or four varieties of Triticum grown in Palestine.

Strong’s Dictionary of Hebrew Words:

Transliteration:
dagan
Phonic:
daw-gawn’
Meaning:
from 1711; properly, increase, i.e. grain
KJV Usage:
corn ((floor)), wheat