Plants certainly have demonstrated all over the earth, that they are quite capable of surviving flood conditions over and over again, have they not? Consider just one tree that the Bible does mention right after the flood ended , the olive tree. While the waters of the Flood undoubtedly did adversely affect many plants and trees, it does not seem improbable that an olive tree might survive them. “The olive tree is quite hardy. It has been said of it that “an old stump will continue to send up new stems, as if its vitality were indestructible.” (The New Schaff-Herzog Encyclopedia of Religious Knowledge, Volume IV, page 404) It is also noteworthy that the Greek philosopher and scientist Theophrastus and the Roman naturalist Pliny the Elder have stated that the olive has grown under water in the Red Sea, retaining its verdure there. So the olive tree might well have remained submerged under water for some months during the Flood without dying. With the abating of the waters an olive tree that had been covered thereby would again be on dry ground and could put forth leaves, so the dove could easily obtain a leaf. The return of the dove with the freshly plucked olive leaf in its bill was of significance to the ark’s human occupants. In that way “Noah got to know that the waters had abated from the earth.”—Genesis 8:11. Source “Insight on the Scriptures” Volume 1, Watchtower Bible and Tract Society

ooooo interesting question.... a loophole...

No he probably did not have two of every Plant although I am not sure about Invertabrates. Christian Fundamentalists usually say that Noah only had Amphibians, Reptiles, Mammals and Birds, about 24,000 species. The Biblical concept of life is different from our own.In Genesis, life is equated with breathing air and being able to move. Plants were not observed to do eather and so were not considered alive. Plants were created earlier on a different day from Animals because they were not condifered to be alive. Fundamentalists usually assume that Fish were ok in the flood and that Invertabrated survived by floating on flood debris. Even today, some Christian Fundamentalists deny that Plants are alive. They base their arguement on the Fall of Man. It is argued that there was no death in the World before the Fall and people and all animals were vegatarian.Obviously, lots of plants were destroyed during eating, but because death entered the World due to the Fall, there cannot have been any death of Plants prior to the Fall. Therefore, Biblically speaking, plants are not and never were alive. It seems that we are supposed to believe that plants just reappeared somehow after the flood. Finally, the Bible only refers to 120 species of Animal, although no attempt is made to systamatically list them. Aristotle listed 350 speciesand the Biblical writers probably knew a similar number. I am not a Fundamentalist though, and I think that the whole story of Noahs Ark is a myth.The Roman Catholic Church and most Protestant Churches believe this as well.

I've heard that Noah was only commanded to bring every animal that breathes with their nostrils....which would include whales, so I don't think that works. But even if you discount whales and just assume that they would have lived through the flood, which makes more sense than God ordering them to be brought onto the ark, there still would not have been enough room for every species. Genesis 6:14-15 says on the dimensions of the ark: "The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits." A cubit is, roughly, equal to about 18 inches. That makes the ark 450 feet long, 75 feet wide, and 45 feet high, and even though that would make the ark the largest wooden ship ever built (I guess God had to hold it together and keep it from leaking), it would still have been too small to hold every species. Of course, there are many Christians who say only certain "kinds" of animals, not species, were taken onto the ark, and they micro-evolved into the various species we have today. Christians will believe anything just to keep their most heartwarming stories of global genocide.