Claviceps purpurea

Parasitic fungus of grasses and cereals that replaces the seed with a dark, banana-shaped sclerotium packed with a complex pharmacopeia of ergoline alkaloids — the chemical lineage from which LSD itself was eventually derived.

Infects rye, wheat, barley, and wild grasses, especially in cool, wet flowering seasons.

• Medieval midwifery (controlling postpartum bleeding)
• Plausibly involved in the Eleusinian Mysteries via the kykeon

Ergot poisoning ('St Anthony's Fire') periodically devastated medieval Europe and is hypothesized to have played a role in episodes attributed to witchcraft. Albert Hofmann's research on ergot alkaloids at Sandoz led to the synthesis of LSD in 1938.

Sclerotia mature on flowering grasses in summer