Star Trek Expanded Universe
For other meanings of "Vulcan", see Vulcan (disambiguation).

Solkar, a Vulcan male

Vulcans (also known as "Vulcanians") are a humanoid species known for their devotion to logic, and stoic natures. Native to the planet Vulcan, they were also a founding member of the United Federation of Planets in 2161.


T'Pol, a Vulcan female.

Vulcans are externally identifiable by their pointed ears, as well as their upswept eyebrows. Several Vulcanoid races descended from the Vulcans also have these characteristics, such as the Romulans, the Debrune, and the Rigelians. The Mintakans may be another offshoot of the parent Vulcan species. (TNG: "Who Watches the Watchers")

Vulcans have a nictitating membrane, or "inner eyelid", that protects them against the harshness of 40 Eridani. (TOS: "Operation: Annihilate!")

Internally, Vulcan blood is copper-based, and is dark green in color. Their heart is where a Human's liver is, and their brains have a noticeable layered structure. Their blood types include T-negative, which is extremely rare. (TOS: "Journey to Babel") One of the more common types is S-indifferent. (Orion Press: "The Choice") Another blood type is T-positive. (Chronicle: "Danse Macabre")

Approximately once every seven years Vulcans enter their mating phase known as the pon farr. During this phase Vulcans experience a neural imbalance (plak tow) causing a loss of emotional control. The Vulcan must then satisfy the pon farr or they could face death. (TOS: "Amok Time", "The Cloud Minders", Star Trek III: The Search for Spock, VOY: "Blood Fever", ENT: "Bounty", "Fallen Hero")

Mel'aneesh salad includes nutrients essential to a Vulcan diet. (Absolute Horizon)

Hybrids of Vulcans and other species became less and less rare in the 22nd through 24th centuries, though they required medical intervention for the pregnancies to go to full term. (TOS novel: The Vulcan Academy Murders; TOS novel: The IDIC Epidemic) Hybridization of Vulcans and other telepathic species (such as Betazoids, or even Terrans with high esper ratings) often resulted in the offspring having Kowalczyk's Syndrome. (Star Trek: Shadowstar Station: "Through the Looking Glass")

One notable difference between Vulcans and Romulans was the amount of lead in their bodies. The Romulan worlds are higher in lead, which is harmless to Vulcanoids. While attempting to go undercover to investigate what was believed to be a group of renegade Vulcans, T'Noshi identified one of the group as being a Romulan spy, because she had undergone recent chelation therapy to remove the lead from her body. (Starship Tristan: Deception)


The traditional Vulcan introduction consists of "name, child of father's name, child of grandfather's name". Example: "Sarek, child of Skon, child of Solkar."

Historically, male Vulcan names start with the letter "S" to honor Surak, the father of Vulcan logic, and female Vulcan names begin with "T" to honor T'Plana-Hath), the matron of Vulcan philosophy.

Vulcan males, at least, undergo a trial by ordeal, the kahs-wan, at age 7. If completed successfully, they are considered adults in Vulcan society. (TAS: "Yesteryear", Orion Press: "Contempt of Council")


After centuries of bloody wars and untold violence on the Vulcan homeworld, roughly around the 4th century on Earth, the Vulcan embraced the teachings of Surak. Since then, the Vulcans have tried to be logical beings, attempting to hide their emotional and passionate core behind a facade of non-expression.

The date of the Surakian revolution differs according to continuity. As well, in many continuities, the revolution was also the impetus -- for those who would one day call themselves Romulans -- to leave Vulcan. (TOS novel: The Romulan Way, TOS novel: Spock's World)

By the mid-22nd century, Vulcans had lost the original meaning of Surak and began to revert to their original state, engaging in territorial disputes and minor wars with Andoria, until Syran and Jonathan Archer was able to recover the Kir'Shara, the body of the original writings of Surak. (ENT: "Kir'Shara")

Per the Star Trek Star Charts, Vulcan's world government, the Confederacy of Surak, was established in 370 A.D.

Tuvok, a Vulcan in Starfleet.

The Vulcans joined the United Federation of Planets in 2161, as one of the four founding members. The Vulcans have since served on Federation Starfleet vessels in multiplying numbers, including all-Vulcan ships in the 23rd (TOS: "The Immunity Syndrome") and 24th centuries. (DS9: "Take Me Out to the Holosuite")

By the 31st century, Romulans had become part of the Vulcan populace, and the planet was renamed Ni'Var. Ni'Var left the Federation sometime after the events of The Burn. (DIS: "Unification III")

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For six decades, ending in 2229, Vulcan isolated itself against outworlders. ("Vulcanis")

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