Evolution doesn't always tend towards larger, more complex organisms. The dinosaurs' closest living relatives are pigeons and sparrows. Similarly, the tiny, shy aquatic quillworts (Isoetes) descend from "scale trees" that dominated great rainforests 300 million years ago and could've outgrown a 9-story building.

It is possible, using only materials that can be found in the average garage or hardware store, to completely foil a plant's sense of gravity. You can grow plants in orbit from your backyard.

The largest herb in the world is the banana "tree". Since it never forms true wood, or even anything closely analogous to wood, it's not a tree but a herbaceous plant... admittedly, one that can grow to almost 8 meters tall!

What we call "a flower" isn't always just a flower. Often, it's actually a mass of several, tens, or even hundreds of tiny flowers -- an inflorescence -- condensed until it looks like one unit, sometimes with extra "petals" formed from tissues that aren't flowers at all. Jack-in-the-pulpit, dandelions and daisies, and poinsettias are all good examples of this particular weirdness.

Plants get sunburn, too, and it's bad for them for a lot of the same reasons that it's bad for us: it damages their DNA, frequently killing cells outright. To fight sunburn, they actually make natural sunscreens -- chemicals called flavonoids, which are transparent to visible light but opaque to dangerous UV.

The vast majority of wood is actually dead tissue -- but that doesn't mean it's not important. Just as hair or fingernails matter to a human, a tree would miss its wood very badly if the dead part were gone.

The delicate, translucent leaves of filmy ferns (family Hymenophyllaceae) are only one cell thick -- but some of them grow to over half a meter long!