Bundahishn 9

The conflict waged with plants was that when they became quite dry.

Amerôdad the archangel, as the vegetation was his own, pounded the plants small, and mixed them up with the water which Tistar seized, and Tistar made that water rain down upon the whole earth.

On the whole earth plants grew up like hair upon the heads of men.

Ten thousand of them grew forth of one special description, for keeping away the ten thousand species of disease which the evil spirit produced for the creatures; and from those ten thousand, the 100,000 species of plants have grown forth.

From that same germ of plants the tree of all germs was given forth, and grew up in the wide-formed ocean, from which the germs of all species of plants ever increased.

And near to that tree of all germs the Gôkard tree' was produced, for keeping away deformed (duspad) decrepitude; and the full perfection of the world arose therefrom.