The Rabbis of the Talmud argued that “each according to its kind” was solely in conjunction with the trees, and that other plants followed suit by the example of the trees, but not through explicit divine instruction:
For when the Holy One, blessed be He, enjoined after its kind upon the trees, the plants applied unto themselves an a fortiori argument, saying: ‘If the Holy One, blessed be He, desired a motley growth, why did He enjoin “after its kind” upon the trees? Moreover, is there not here an a fortiori argument? If upon trees which by nature do not grow up in a motley growth the Holy One, blessed be He, enjoined “after its kind”, how much more so does it apply to us’! Immediately each plant came forth after its kind.
Targum Onkelos: And the Lord said, The earth shall bring forth grass; the plant whose germ‑seed* is to be sown; the fruit‑tree making fruit according to its kind, whose germ‑seed is in it upon the earth;‑and it was so. *Lit., “son-seed.”
Rashi: Let the earth sprout vegetation, seed yielding herbs: דֶּשֶׁא does not have the same meaning as עֵשֶׂב, and עֵשֶׂב does not have the same meaning as דֶּשֶׁא. And it would have been inappropriate for the Scriptural text to use the expression, תַּעֲשִׂיב הָאָרֶץ (let the earth bring forth herbs), for there are various species of דֶּשֶׁא, each one by itself which is called a particular עֵשֶׂב. And it would not be the correct term for the speaker to say, “such-and-such a דֶּשֶׁא,” because the term דֶּשֶׁא applies to the earth’s covering, when it is filled with vegetation.
Let the earth sprout: Let it be filled and covered with a mantle of herbs. In Old French, דֶשֶׁא is called erbediz, herbage, all in a mixture, whereas each root individually is called עֵשֶׂב.
seed-yielding: That its seeds should grow in it from which to sow elsewhere.
fruit trees: That the taste of the tree should be like the taste of the fruit. It [the earth] did not do so, however, but“the earth gave forth, etc., trees producing fruit,” but the trees themselves were not fruit. Therefore, when man was cursed because of his iniquity, it [the earth] too was punished for its iniquity (and was cursed-not in all editions). – [from Gen. Rabbah 5:9]
in which its seed is found: These are the kernels of every fruit, from which the tree grows when it is planted.
Rambam: God willed that, in the four elements, there be a force which makes things grow and produce seed so that each species be able to reproduce; and that, from that force, there grow small plants and shrubs as well as large, seed-bearing plants and fruit-bearing trees; and it is so forever.
Ibn Ezra: On the third day, God said effortlessly, “Let the earth use its inherent power to produce plant life on the earth — grasses which produce seed and fruit trees which produce fruit — each according to its kind, bearing its seed in its fruit.” When this was so,