Genesis 1:11

"Let the earth bring forth grass (desheh esev):" Desheh is not an expression of esev and esev is not an expression of desheh, and [so] the expression of Scripture could not have [been], taasiv haarets [exchanging one word for the other]. Since types of deshaim are divided, each one by itself is called a certain esev. And it is not common parlance to say a certain desheh, since desheh is an expression of covering the earth when it is full of grasses.

"Let the earth bring forth:" Let it be filled and covered with a mantle of herbs. In [Old French], desheh is called erbediz [a collective of herbs] all of them in a mixture, whereas each root individually is called esev.

"That produces seed:"That its seed should grow in it, so as to sow from it in a different place.

"Fruit trees:" That the taste of the tree should be like the taste of the fruit. And [the earth] did not do so, but rather (verse 14) “the earth gave forth, etc. trees producing fruit,” and the trees [themselves] were not fruit. Therefore, when man was cursed because of his iniquity, it [the earth] too was remembered for its iniquity and was cursed.

"The seed of which is in it:" These are the pits [seeds] of every fruit, from which the tree grows when it is planted.

And the Lord said, Let the earth increase the grassy herb whose seed seedeth, and the fruit-tree making fruit after its kind, whose seed is in itself upon the earth. And it was so.

And He said - the text states "Let the earth bring forth grass", "let them swarm", "let the earth bring forth" - behold, He placed a power within the earth and the water to do [these] at the command of Hashem, and this is the [concept of] regeneration / procreation.

The meaning of "let it bring forth grass" is like "let it grow" (tatzmiach) ["let it bring forth plants"]

AND G-D SAID: ‘LET THE EARTH PUT FORTH GRASS.’ He decreed that there be among the products of the earth a force which grows and bears seed so that the species should exist forever. It is possible that the name “earth” mentioned in the first verse already contains a hint that a force which causes things to grow should spring up from the earth, and it was from this force that the foundations of all vegetations according to their kinds emanated. From them sprang the grass and trees in the garden of Eden, and from them came those in the world. This is what the Rabbis have said: “On the third day He created three creations: trees, grass, and the garden of Eden.” They have also said: “There is not a single blade of grass below [that does not have] a constellation in heaven that smites it and says to it, ‘Grow.’ It is this which Scripture says, Knowest thou the ordinances of the heavens? Canst thou establish ‘mishtaro’ (the dominion thereof) in the earth? — [mishtaro being derived from the root] shoter (executive officer).”
And He said that all this vegetation should be after its kind. This is the basis of the prohibition of sowing mixed kinds of seeds, since he who sows them works contrary to the power of the work of creation. I will yet explain this with the help of G-d.
Now Rabbeinu Shlomo [Rashi] wrote: “Deshe essev (grass, herb). Deshe does not mean the same as esev and esev does not mean the same as deshe, for by deshe is meant that which forms the covering of the ground when it is filled with vegetation, and it is not linguistically correct to say ‘this or that deshe.’ Each by itself is called this or that esev.”
This interpretation of Rashi is not correct. For if it were so, the word deshe could have no plural, and yet we find the Sages saying, “If a person grafted together two kinds of deshaim, what should the law be?” And the Rabbi himself (the Rabbi, the Master) without specification of the name is used by Ramban only with reference to Rashi or Rambam. It is the highest mark of respect. Precedent for it is found in the Talmud where just the title Rabbi meant Rabbi Yehudah Hanasi, redactor of the Mishnah, and the title Rav was a reference to Abba Arucha, founder of the Babylonian Academy of Sura. mentions deshaim. are different; each by itself called this or that esev.” Rather, deshe is the young growing plant, …

דשא, every kind of herb collectively is known as דשא whereas every individual type of herb is known as עשב.

עושה פרי למינו, according to the plain meaning of the text the word למינו here refers to the herbs. When the word occurs again in connection with the trees, it includes the עשב which the text had defined as carrying within it its own seed.

עושה פרי למינו, an apple tree would produce apples, not dates.

אשר זרעו בו, the seed would be within the fruit, not within the trunk. This would enable man to plant this kind of tree as well as others, each of their respective species.

דשא, herbs fit for consumption by animals. We find this expression used in this sense in Yoel 2,22כי דשאו נאות מדבר, “for its herbs (the ones for the beasts) are found in the pastures of the wilderness.”

עשב מזריע זרע, for consumption by human beings.

עץ פרי עושה פרי למינו, if it were a mixture of more than one species it would not be able to reproduce itself.

ויהי כן, it endured, in its original format, not becoming adulterated nor shedding any of its individuality. Had it absorbed parts of competing species it could not have procreated itself.

ויאמר אלוקים תדשא הארץ דשא, on the third “day”. G’d commanded the earth to produce vegetation, in other words, He equipped the earth with the ability, potential, to grow plants of different kinds. This was the second instance in which elements were amalgamated, i.e. employed in conjunction with one another, the product comprising more than one of the basic elements. (compare verse 9) The purpose of these various plants was to serve as food for the land-based living creatures which had not yet been created. The living creatures created on the fifth and sixth day respectively, formed the third stage of employing different elements in conjunction with one another, i.e. in a still more sophisticated manner.
The meaning of the word תדשא is equivalent to תוציא דשא, “bring forth herbs.” This דשא must be viewed as a relatively primitive form of grass, a forerunner of the eventual grass, so that a special verb is used to describe this process. The prophet Yoel 2,22 uses the word in that sense when describing primitive plants growing in the desert. Both the words צמח and דשא describe either primitive plants, or plants which have not yet grown to their full extent. The activities of the luminaries on the third day were relatively weak, not comparable to the power assigned to them on the fourth day, as we already mentioned in our commentary on verse 3. Only on the fourth day did their power increase sufficiently to materially influence the atmosphere covering the surface of the globe. As a result, plants of an advanced calibre were then produced by the earth, the trees growing to their full height, etc.
This is what is meant by the words spoken by G’d on the fourth day: להאיר על הארץ, i.e. to make their impact felt all over the surface of the earth. This is also what Moses referred to in Deuteronomy 33,14 וממגד תבואות שמש, וממגד גרש ירחים. The meaning of the word להאיר, usually understood only as “to provide illumination,” is in fact twofold. It means “to give light,” as well as “to carry out its assigned tasks.”

דשא, עשב. “deshe” which would develop into “eyssev.” Once it had attained maturity, it would grow seed by means of which to perpetuate itself. Other commentators (Nachmanides) view דשא as a primitive herb which does not produce seed, whereas עשב is a superior kind of herb producing seed.