Mapping the world's entheogenic genomes.

Long before they carried a Latin name, some of these mushrooms were gathered in the highlands of Oaxaca and used in Mazatec ceremony. In the mid-twentieth century that knowledge entered print, then the counterculture of the 1960s, and from there a lasting current in art, music and inward life. Half a century later, the same chemistry sits at the center of the psychedelic renaissance: clinical research, new institutions, a public argument about mind and medicine. The molecule became famous. The organisms that make it did not.

What they make is more than one compound. From tryptophan they produce psilocybin and related tryptamines (baeocystin, norbaeocystin, norpsilocin) and, by a separate route from the same pool, β-carbolines that inhibit monoamine oxidase A, the enzyme that degrades psilocin: the active compounds and a brake on their breakdown, inside one organism. Their habitats range from wood and dung to grassland and cloud forest; their secondary chemistry interests both therapeutics and environmental science. For fungi this culturally charged, the biochemistry is still only partly known.

That chemistry has a deep evolutionary life. The genes for psilocybin sit in a cluster that appears in more than one architecture across the deepest splits in these lineages, and has entered unrelated mushrooms repeatedly since the Eocene.Psilocybe, the most heavily sequenced genus among them, still has a published assembly for fewer than one in ten accepted species. Across the wider family, most taxa have none.

Origin, transfer and this alkaloid repertoire cannot be resolved until the family is mapped at genome scale.