Bosmer means "tree-sap people"
Bosmer have been at war with the Khajiit for years. The Bosmer see everything within the Valenwood as their territory, and left alone the Valenwood grows to cover the deserts of Elsweyr. The Khajiit set the edges of Valenwood on fire every so often to keep the Bosmer from encroaching, which the Bosmer see as an act of desecration. If you see a Khajiit with a torch, SHOOT HIM IN THE FACE!
Devout Bosmer take the green oath, which forbids them from harvesting or eating plant matter. They can make use of plant matter that other races have harvested, but the truly devout won't even do that. Bosmer traditionally make their bows and arrows from laminated bone. They are carnivores.
Devout Bosmer sometimes file their teeth into points as a show of piety.
The heart of a skooma-addicted Khajiit is a delicacy to a Bosmer. (The skooma makes the meat sweeter.)
Bosmer like to get drunk off of some kind of punch made from fermented blood. It causes hallucinations in Imperials.
When Valenwood is under dire threat, the Bosmer can go nuclear. A group of devout Bosmer perform a secret ritual that transforms them into murderous, ravenous beast-folk. The group, called the Wild Hunt, tears through the wood, eating everything in its path, until there is nothing left to devour. Then the group devours itself in a cannibalistic orgy of destruction. The Bosmer believe that the monsters that stalk Nirn are all remnants from past Wild Hunts. They can still communicate to some extent with these transformed Bosmer, which is where the Bosmer get their Beast Tongue racial power.
In Morrowind there was an eye option for Bosmer that gave them completely black eyes. Kind of creepy. They took it out in Oblivion, but modders put it back in. I like to think that the black eyes signifies Bosmer who witnessed a Wild Hunt and somehow survived. (But that's my own made-up lore.... just thought I'd share.)
So. Pretty elves in green tights? Not so much.
I love the Bosmer!

