Biogenetic precursor of all indole alkaloids is the amino acid tryptophan. For most of them, the first synthesis step is decarboxylation of tryptophan to form tryptamine. Dimethyltryptamine (DMT) is formed from tryptamine by methylation with the participation of coenzyme of S-adenosyl methionine (SAM). Psilocin is produced from dimethyltryptamine by oxidation and is then phosphorylated into psilocybin.
In the biosynthesis of serotonin, the intermediate product is not tryptamine but 5-hydroxytryptophan, which is in turn decarboxylated to form 5-hydroxytryptamine (serotonin).
Psilocybin mushroom spores are legal to possess in every state in the United States, except California, Georgia, and Idaho. This is because it is psilocybin and psilocin (the active chemicals in psychedelic mushrooms) which are specifically listed in Schedule I, not the mushrooms themselves. Theoretically any plant or mushroom which contains psilocybin may be considered a "container" of psilocybin which makes the plant illegal also. However, mushroom spores do not contain psilocybin or psilocin. For this reason, they are not illegal either federally or in most states.
California, Georgia, and Idaho have specifically passed laws which make it illegal, at least in some situations, to possess spores that produce psilocybin-containing mushrooms.
Federal law in the United States does not mention psilocybin mushroom spores.
There are three interesting things about the California law regarding spores. The law appears to state that it is only illegal to import spores into the state if there is intent to cultivate them into mushrooms. It is not specifically illegal to possess spores, it is only illegal to "transport, import into the state, sell, furnish, or give away" spores or mycelium if they are intended to be cultivated or used to produce psilocybin-containing mycelium or fungi. Only viable spores appear to be illegal as the law specifically states that it is "spores or mycelium capable of producing mushrooms" which are illegal.
Health & Safety Code Section 11390-11392
11390. Except as otherwise authorized by law, every person who, with intent to produce a controlled substance specified in paragraph (18) or (19) of subdivision (d) of Section 11054, cultivates any spores or mycelium capable of producing mushrooms or other material which contains such a controlled substance shall be punished by imprisonment in the county jail for a period of not more than one year or in the state prison.
11391. Except as otherwise authorized by law, every person who transports, imports into this state, sells, furnishes, gives away, or offers to transport, import into this state, sell, furnish, or give away any spores or mycelium capable of producing mushrooms or other material which contain a controlled substance specified in paragraph (18) or (19) of subdivision (d) of Section 11054 for the purpose of facilitating a violation of Section 11390 shall be punished by imprisonment in the county jail for a period of not more than one year or in the state prison.
11392. Spores or mycelium capable of producing mushrooms or other material which contains psilocyn or psyoclyin may be lawfuly obtained and used for bona fide research, instruction, or analysis, if not in violation of federal law, and if the research, instruction, or analysis is approved by the Research Advisory Panel established pursuant to Sections 11480 and 11481.
Code Section 16-13-71 (627)
(a) A "dangerous drug" means any drug other than a drug contained in any schedule of Article 2 of this chapter, which, under the Federal Food, Drug, and Cosmetic Act (52 Stat. 1040 (1938)), 21 U.S.C. Section 301, et seq., as amended, may be dispensed only upon prescription. In any civil or criminal action or other proceedings, a certification from the Food and Drug Administration of the United States Department of Health and Human Services attesting to the fact that a drug other than a drug contained in any schedule of Article 2 of this chapter involved in the action or proceeding is a dangerous drug that federal law prohibits dispensing of without a prescription pursuant to the Federal Food, Drug, and Cosmetic Act shall be admissible as prima-facie proof that such drug is a "dangerous drug."
(b) In addition to subsection (a) of this Code section, a "dangerous drug" means any other drug or substance declared by the General Assembly to be a dangerous drug; to include any of the following drugs, chemicals, or substances; salts, isomers, esters, ethers, or derivatives of such drugs, chemicals, or substances which have essentially the same pharmacological action; all other salts, isomers, esters, ethers, and compounds of such drugs, chemicals, or substances unless specifically exempted and the following devices, identified as "dangerous drugs":
(627) Mushroom spores which, when mature, contain either psilocybin or psilocin;
Idaho Schedule I (d) Hallucinogenic substances. Any material, compound, mixture or preparation which contains any quantity of the following hallucinogenic substances, their salts, isomers and salts of isomers, unless specifically excepted, whenever the existence of these salts, isomers, and salts of isomers is possible within the specific chemical designation (for purposes of this paragraph only, the term "isomer" includes the optical, position and geometric isomers): ... (32) Spores or mycelium capable of producing mushrooms that contain psilocybin or psilocin."