Kilayim, Chapter One, Mishnah One
Our mishnah teaches that if two types of seeds, either grains or beans, are very similar to one another then they are not kilayim and one can plant a field with both of them mixed. Kilayim is prohibited only in cases of two distinct species of seed; if the two are almost interchangeable, then there is no prohibition. The mishnah therefore lists pairs of seeds that are not kilayim with each other. Since the mishnahs meaning is quite simple, I have refrained from commenting below.
One problem in interpreting and translating this mishnah is that it is difficult to identify many of the species mentioned. Albeck provides various Latin terms, and all commentators attempt to identify the species, but some of their meanings have probably been lost. To avoid this problem, I have transliterated some of the terms rather than translate them. Thus zunin instead of Cephalaria Syriaca or sapir instead of Vicia Narbonensis. I realize that this may disappoint the hard-core botanists among you, but I cant write these Latin terms and pretend I know what they are. The most important thing to know is that in each pair, the two species are very similar. So while I might not know what zunin is, I know it is similar to wheat.
1) Wheat and zunin do not constitute kilayim one with the other.
2) Barley and oats, spelt and rye, or beans and sapir (a type of bean), or purkdan and tofah (two similar types of beans), or white beans and kidney beans, do not constitute kilayim one with the other.