Paul D Stewart / Historical illustration of Mandrake (Mandragora officinarum) flowers and fruits from the Paris Royal Botanic Garden. Engraving by Stumpf, in 'Dictionarium, Historicum, Criticum, Chronologicum, Geograp...

Nigel Cattlin / Purple spotted stems characteristic of Hemlock (Conium maculatum) hollow and poisonous, Devon, July

Nigel Cattlin / Purple spotted stems characteristic of Hemlock, (Conium maculatum) hollow and poisonous, Devon, July

Nigel Cattlin / Large flowering Hemlock (Conium maculatum) plants beginning to go to seed, Devon, July

Nigel Cattlin / Ergot (Claviceps purpurea) sclerotium on cocksfoot grass (Dactylis glomerata) seedhead in late summer, Berkshire, September

Nigel Cattlin / Sap / latex exuding from cuts in the seedpod of an Opium poppy (Papaver somniferum) an annual garden ornamental and a source of opiate narcotics