# Why do plants waste the green part of the sunlight? **URL:** \ **Category:** Factual Questions\ **Created:** [July 22, 2001, 12:39pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437 "2001-07-22T12:39:29Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![femtosecond](https://avatars.discourse-cdn.com/v4/letter/f/f08c70/32.png) [@femtosecond](https://boards.straightdope.com/u/femtosecond)\ **Post date:** [July 22, 2001, 12:39pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/1 "2001-07-22T12:39:29Z")
Would it need more energy to build up a better photosynthesis pigment than it would yield? Would dark plants get warmer, losing more water? At least in cold, dark, humid climate, black plants should do much better. Imagine all those cute little deers bumping their nose in a pitch black forest… ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [July 22, 2001, 5:28pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/2 "2001-07-22T17:28:34Z")
Well, OK, what other pigment captures the energy of sunlight even as well as chlorophyll does? Until something evolves a substance of a color other than green that can do the same job the green part of spectrum is going to stay unused. ---
**Author:** ![TheeGrumpy](https://avatars.discourse-cdn.com/v4/letter/t/779978/32.png) [@TheeGrumpy](https://boards.straightdope.com/u/TheeGrumpy)\ **Post date:** [July 22, 2001, 5:38pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/3 "2001-07-22T17:38:58Z")
The quandry here is that plants are green because they reflect the middle part of the spectrum, preferring to absorb energy from the fringes of visible light: red and blue/violet. Wouldn’t it be easier for plants to target the center of the spectrum, absorbing yellow/green/blue and reflecting purplish-brown? The hypothesis I recall reading about is that the ancestors of all green plants were once the lowly competitors to the red- and blue-reflecting types. Perhaps they sat beneath the other types in a pool of water, absorbing the spectrum fringes which was the only light that trickled down after the competitors gobbled up the rest. Then something happened to the (seemingly more sensible) competitors, leaving us with green-reflecting plants. I can’t find a citation for this hypothesis, and I’m not sure if the federally funded [Deep Green Project](http://ucjeps.berkeley.edu/bryolab/greenplantpage.html) supports or refutes that old hypothesis. Here’s another article which refers to an interesting but [unrelated finding](http://seattletimes.nwsource.com/news/health-science/html98/plnt_19990805.html) from Deep Green. According to this, the predominant green color of plants is an accident that stuck. And how! ---
**Author:** ![TheeGrumpy](https://avatars.discourse-cdn.com/v4/letter/t/779978/32.png) [@TheeGrumpy](https://boards.straightdope.com/u/TheeGrumpy)\ **Post date:** [July 22, 2001, 5:41pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/4 "2001-07-22T17:41:34Z")
The quandry here is that plants are green because they reflect the middle part of the spectrum, preferring to absorb energy from the fringes of visible light: red and blue/violet. Wouldn’t it be easier for plants to target the center of the spectrum, absorbing yellow/green/blue and reflecting purplish-brown? The hypothesis I recall reading about is that the ancestors of all green plants were once the lowly competitors to the red- and blue-reflecting types. Perhaps they sat beneath the other types in a pool of water, absorbing the spectrum fringes which was the only light that trickled down after the competitors gobbled up the rest. Then something catastrophic happened to the (seemingly more sensible) competitors, leaving us with green-reflecting plants. I can’t find a citation for this hypothesis, and I’m not sure if the federally funded [Deep Green Project](http://ucjeps.berkeley.edu/bryolab/greenplantpage.html) supports or refutes that old hypothesis. Here’s another article which refers to an interesting but [unrelated finding](http://seattletimes.nwsource.com/news/health-science/html98/plnt_19990805.html) from Deep Green. ---
**Author:** ![TheeGrumpy](https://avatars.discourse-cdn.com/v4/letter/t/779978/32.png) [@TheeGrumpy](https://boards.straightdope.com/u/TheeGrumpy)\ **Post date:** [July 22, 2001, 5:44pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/5 "2001-07-22T17:44:32Z")
The quandry here… The hypothesis I recall reading about… I can’t find a citation for this hypothesis. Here’s a link to the federally-funded [Deep Green Project](http://ucjeps.berkeley.edu/bryolab/greenplantpage.html). I’m not sure if their findings support or refute the hypothesis I mention. Here’s another article which refers to an interesting but [unrelated finding](http://seattletimes.nwsource.com/news/health-science/html98/plnt_19990805.html) from Deep Green. ---
**Author:** ![TheeGrumpy](https://avatars.discourse-cdn.com/v4/letter/t/779978/32.png) [@TheeGrumpy](https://boards.straightdope.com/u/TheeGrumpy)\ **Post date:** [July 22, 2001, 5:45pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/6 "2001-07-22T17:45:44Z")
Here’s the link for Deep Green. [http://ucjeps.berkeley.edu/bryolab/greenplantpage.html](http://ucjeps.berkeley.edu/bryolab/greenplantpage.html) ---
**Author:** ![GargoyleWB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gargoylewb/32/199_2.png) [@GargoyleWB](https://boards.straightdope.com/u/GargoyleWB)\ **Post date:** [July 22, 2001, 7:20pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/7 "2001-07-22T19:20:24Z")
My own seat-o-the-pants theory… I think it is merely an evolutionary holdover from when chlorophyll developed in algae and small cellular-colony sized plants in the oceans. If you’ve been under water, green wavelengths seem to be absorbed very quickly by water (green things appear much darker, even black) so chlorphyll didn’t have much green energy to absorb down there and never developed the ability. By the time plants made it onto land, the photosynthesis process was too hard-wired to adapt to make use of the green wavelengths. ---
**Author:** ![femtosecond](https://avatars.discourse-cdn.com/v4/letter/f/f08c70/32.png) [@femtosecond](https://boards.straightdope.com/u/femtosecond)\ **Post date:** [July 22, 2001, 8:34pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/8 "2001-07-22T20:34:52Z")
So plants, being not very smart, didn’t notice yet there’s no light-stealing competitor around anymore? But nature evolved many accessory pigments, beside A there’s Chlorophyll B,C,D,E, Phycoerythrin, Phycocyanin, ß-Carotene, Xanthophylls… taking care of other parts of the spectrum. They can’t be all _that_ old. And elodea, an aquarium plant, uses more red light than green! But in the wavelength/absorption diagram, there’s still a hole in the green. No, IANAGolfer 🙂 Maybe it’s really just because deers wouldn’t dung a dark forest… ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [July 22, 2001, 9:18pm UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/9 "2001-07-22T21:18:14Z")
There are plants with black leaves, like this one: [Ophiopogon Planiscapus](http://www.desert-tropicals.com/Plants/Liliaceae/Ophiopogon_planiscapus.html) (the photo doesn’t do it justice). ---
**Author:** ![regnad\_kcin](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@regnad\_kcin](https://boards.straightdope.com/u/regnad_kcin)\ **Post date:** [July 23, 2001, 12:27am UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/10 "2001-07-23T00:27:22Z")
Speaking as an idiot who knows nothing about plants, I cant help but notice theres a bush with red leaves growing in my front yard. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [July 23, 2001, 2:29am UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/11 "2001-07-23T02:29:44Z")
quandary - Function: noun - Inflected Form(s): plural -ries a state of perplexity or doubt ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [July 23, 2001, 9:39am UTC](https://boards.straightdope.com/t/why-do-plants-waste-the-green-part-of-the-sunlight/73437/12 "2001-07-23T09:39:35Z")
Anyway, the explanation is obvious; it must be God’s favourite colour. \