#(I am not a botanist or a biologist but I'd love to talk about SPECIFICALLY how this would work with someone who is haha :))

[ihavetoomuchhomeworkforthis]

So I found this on Google, and I accidentally ended up having a megabrainstorm session with my dad about if Vulcans were actually photosynthetic, or really just how photosynthetic humanoids would work in general and how they'd function on a Starfleet ship? It was more like me ranting excitedly at my dad for a few minutes, but there were some cool ideas in there. (I mean I think they're cool, hopefully you guys do too)

Warning: EXTREMELY long (and nerdy) bullet point list follows under the cut

green skin because chlorophyll

possibly even leafy skin, which might end up looking more like scales, but with patches of softer more leaf-like areas where we'd have more body fat and/or body hair

(they can still have that Vulcan hair though, since it's sort of a defining trait/style of the species in Star trek)

This means they have to absorb sunlight through their skin, and convert it into energy in the form of glucose, like trees

Therefore they'd have to have glucose (not copper) based blood (but the melting point of sugar is really high? Hadn't quite worked that part out)

Their blood would be white then? Amber, like tree sap. Wait actually don't some flowers/green stemmed things have white sap in the stems? (Maybe their blood would change from white to amber as they age? I know flowers aren't younger versions of trees, but it would be cool)

and they'd have to drink water just as much as humans because plants need water (as Chekhov is panicking about) but maybe since Chekhov is worried about "watering" spock, their hair can function like roots or something to soak up extra water as well. Idk if it rains much on Vulcan but when it did they'd all be going outside like the worms do on Earth lol

They wouldn't really have to eat if sunlight is their primary energy source. Their mouth would be just for water, breathing, and speaking. In which case they'd have ALL different organ systems, seeing as our digestive system takes up a good chunk of space in the torso, what would they fill it with? Being humanoid, they'd still need lungs, as well as a heart to circulate the (glucose based?) blood. They can still have a liver as a toxin filter and whatever else livers do (trees have to deal with not-so-clean water, so the photosynthetic Vulcans could probably deal with pretty muddy/questionable water as well. And maybe that connects to a very basic digestive system (liver-filters > short and singular intestine > rectum) which is mostly just for getting rid of the mud (yes, pooping.) And the liver can also deal with dusty/sandy air probably. Oh they might not need to eat (maybe even CAN'T eat since they wouldn't need or have the organs to deal with it) but they could drink liquids other than water, and it might be helpful/necessary to drink sugary fruit drinks if it's been cloudy for a few days, because humanoids expend a LOT more energy than plants probably do. They probably have a "stomach" which acts as a storage and distribution-into-bloodstream area for water and sugar, a little like how a camel's hump works, so it might not only be "OMG did anyone water Spock today!?" But also "OMG Spock fainted, somebody get him fruit juice!" *frantic running to the mess hall* *20 ccs of sugar* "I told you to drink more sugary stuff, our artificial light here just can't give you as much energy as your THREE ENTIRE SUNS back home, you ****ing idiotic hobgoblin!" *definitely not crying over Spock's wellbeing*

Idk what would make up the rest of their torso since they don't need as much space for organs. Heart, lungs, liver, one intestine + waste management, storage stomach, and the rest of ours is primarily taken over by about 15 feet of scrunched intestines, so maybe for them it's all leg, or they could maybe have a redundant extra pair of lungs, and/or another heart, especially to lessen the workload since tree sap is significantly thicker than human blood? Or maybe all the water would thin it out? Or one heart is more connected to the skin where they absorb light energy and cycles the glucose-based blood (which goes from white to amber as they grow up) and the other heart connects more to the water/fruit juice storage stomach and cycles water as well as somehow sends old water off to get peed out? And they should also have an organ that somehow counters sunburn and helps then deal with their world's elevated levels of radiation.

So: two pairs of lungs (for no real reason), two hearts (and two circulatory systems?), one for water and one that's more for the nutrients of glucose from sunlight, a storage stomach, a liver, an organ that deals with radiation and sunburn, a short intestine for the undrinkable parts of potentially muddy/contaminated water, the rectum to poop out the mud, the kidneys/bladder/urinary system for old water, and I think that's it.

I've been occasionally researching (googling) during the process of writing this, and I found that trees actually do have 2 different kinds of sap! Phloem is the "more nutrient rich form, and flows from the leaves bringing sugars and hormones to nutrient-hungry parts of the plant," while Xylem "consists mostly of water" so it's perfectly reasonable for them to have 2 hearts, one for each kind!

But how can we design starships to be more Vulcan-friendly then, if they need so much light? Well first of all, having sugar as an option for hyposprays in the medbay/sickbay, as well as plenty of sugary drinks available in the replicators, and the sugary fruit drinks shouldn't "cost" as much in rations since the Vulcans sort of need it as much as they need water when they aren't able to access direct sunlight. Speaking of which, all the hallways should have strips of light off to the side (one on the floor and another shining down from the ceiling above it) that the Vulcan crewmembers can walk through, and there should be a solarium room which does its best to replicate at least the lighting and radiation conditions of Vulcan (the planet). This solarium should have the light panels be able to slide away to reveal actual windows, and starships with any Vulcans in their crew should be required to spend a minimum amount of time every so often in orbit of an actual sun or star system so that the Vulcans can have genuine sunlight. It would be really funny if Spock just had a spotlight that follows him around like Olaf's snow cloud in Frozen, but it would be more practical if his station on the bridge just had extra light panels which are positioned in some way so as not to shine in his eyes. Also, this photosynthesis sort of depends on their skin actually being exposed to light, so the uniform would probably be modified for Vulcans to be short sleeves and shorts despite how weird that would be, or it would be designed like tinted glass somehow, or... some other way of letting the light in without being immodest, idk

And now for a very important question: some trees are deciduous, yes? Oh dang it I just googled whether Vulcan has seasons and the answer was no. Scrolling down pointed out that Vulcan is a desert planet and so they'd naturally be able to go without water for longer periods of time than humans. That second one is okay, that's why they have a water storage organ sort of like camels, and I guess maybe they wouldn't need so much water after all. More like cacti than trees. But the no axis tilt / no seasons thing sort of cancels out what I was about to write :(

I'll write it anyway. Let's pretend for a second that Vulcan has seasons, because this whole thing can really apply to "photosynthetic humanoids" in general, not just photosynthetic Vulcans in particular. So, I was about to talk about deciduous trees :) When the seasons shift towards winter, the sunlight is weaker, trees go red before losing their leaves and sort of hibernating, right? Well what if Vulcans start going pale, then yellowy, and eventually taking on a pale reddish hue, and since they can't lose their skin to conserve energy, they consume as much sugar/fruit juice as they can over a period of a few weeks, before going into hibernation like bears?

This means that your Vulcan crewmate is kind of useless for at least a quarter of every year, which isn't really a problem unless they're a senior officer, but if they ARE a senior officer, they better have an apprentice or someone who can cover for them while they hibernate. Maybe another Vulcan from the opposite side of the planet, who would naturally hibernate during the opposite half of the year.

Would this Vulcan and their opposite-side-of-the-planet counterpart be best friends, or bitter rivals? Who knows!

Now, starships do not actually have seasons, so the hibernation cycle wouldn't be technically necessary. The Vulcan has two options: either slowly adjust to the year-round availability of sunlight over a period of multiple years so that they don't have to abandon their crew for a few months out of every year (and be SEVERELY messed up if they ever retire and go back to the hypothetical version of Vulcan which has seasons), OR, make sure that the availability of light mimics the seasonal cycle of pretend-Vulcan-with-seasons so that they can have their hibernation cycle properly. (Clearly the better option if they aren't a senior officer, especially if they don't plan to spend the rest of their life on the ship.)

Also it would be really cute to see what kind of pillow fort nest Spock would probably end up making in his quarters to hibernate in. I wonder if they'd visit him.

DO NOT WAKE THE HIBERNATING SPOCK. Google says waking up an animal from hibernation too early can have fatal consequences. On the other hand, it also said bears can wake themselves up immediately to protect cubs if necessary or if they're startled awake, so maybe he can respond to red alerts. However going based off the first point, it might be necessary to completely soundproof his quarters and make sure he remains undisturbed. And yet another possibility is that photosynthetic Vulcans wouldn't need to hibernate at all if they come from a part of the planet which is mostly friendly year-round (which would technically be true, since it doesn't actually have seasons at all, and they would choose to have civilizations in the most habitable areas. Maybe civilizations closer to the poles would have Vulcans that are naturally paler or more reddish, like how the Aenar on the Andorian homeworld are blind and paler.)

Animals coming out of hibernation can have lost up to 30% of their body weight (over a QUARTER), so Vulcans coming out of hibernation would look so sick and weak, and they'd probably take a while to get their full green color back, and the more soft leafy areas of higher body fat would have shriveled into just the small scale-like leaves that make up the majority of their skin, and their uniforms would be all baggy on them, and the human crew would probably be so so so worried for them, especially the first few hibernation cycles

*Spock stumbles onto the bridge for the first time in several months, pale orange-red and extremely skinny* "Oh my god, Spock!" (overjoyed at his return) -- "Oh my god Spock you look like crap, are you alright?" (softer and full of concern upon actually noticing what he looks like) -- "This is perfectly normal, I'll be fine, you need me on du-" *faints*