Why plants are green?

chlorophyll :)

Quick answer, chlorophyll.

Beat you to it, @MissAnthrope ! :P

Chlorophyll? More like borophyll!

:P

What I think is cool is that when the leaves change colors in the fall, it’s the tree preparing for hibernation, so it draws the chlorophyll back into the trunk. The remaining colors of the leaves are the actual colors of the leaf. Chlorophyll dominates when it’s in the leaves, so fall is the only time you can see what the leaves actually look like.

Some plants are not green. I have Indian Pipe growing in my acidic woods in the spring.

Waxy and white, they are beautiful.

http://www.ct-botanical-society.org/galleries/monotropaunif.html

Plants contain chlorophyll, which is the key to their ability to produce energy directly from sunlight. To do this the chlorophyll has to absorb a lot of light. It absorbs most of the spectrum of visible light, with the exception of green wavelengths. Plants that are not green have less chlorophyll compared to other pigments. Most of them, if deprived of light to some extent, will turn green as they produce more chlorophyll in order to obtain the energy they need.

I found this explanation:green light is the less useful light for plants so they reflect green light

Because they are envious of the animal kingdom.

I guess the real question is why aren’t they black?

@ubersiren
lol

@AstroChuck for the win!

@MissAnthrope What!? That’s crazy talk. It’s a really adorable idea, but not the case at all.

Seriously?

@MissAnthrope Yeah! There’s still some chlorophyll in autumn leaves, although production of new chlorophyll slows to a halt. there’s just something about the weather conditions that provokes the carotenoids (pigment responsible for yellow, brown, orange) to flare up and also starts the production of anthocyanins (reds and purples.)

Dang. That’s what I was taught. I feel… even more disillusioned about my education. :P

plants are green because of chlorophyll, but anything is any color because all other wavelengths of light are absorbed by the object. the color reflected is the color we see. i don’t know if anyone already said this.

You know, I actually have a great diagram of this, but I can’t find my notes. The absorption, reflection, and (what we have mostly ignored here) transmission of light by plants is actually pretty complex and interesting. Healthy vegetation has a fairly unique spectral signature that can easily be identified by multi-spectral satellites, and even differentiated from unhealthy vegetation. Pretty cool if you’re a satellite imagery geek.

@gussnarp I’d love to see that diagram. I wasn’t aware of the satellite fact! I’d venture to say it’s pretty cool if you’re any kind of geek. :)

@Beta_Orionis I should be able to dig it up. I think it was only on my hard drive that crashed, but a friend of mine is still TA for that class and would send it to me if I ask. I could post it on flickr or something and link to it, I imagine.