Sforno on Genesis 1:11/ספורנו על בראשית א׳:י״א

1דשא, 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.”

2עשב מזריע זרע, for consumption by human beings.

3עץ פרי עושה פרי למינו, if it were a mixture of more than one species it would not be able to reproduce itself.

4ויהי 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.