Ergot of Rye

(Claviceps purpurea Tulasne, Ascomycetes)

Also called: Rye ergot, Secale Cornutum.

Description: Ergot of rye is the autumnal form of a parasitic fungus found on rye, rarely on other cereals or members of the Gramineae. The infected rye flower develops a black mass resembling a grain of corn in place of the destroyed ovary. These ergot 'grains' are 1-4cm (0 4-1 5in) long, more or less cylindrical, often fissured, generally purplish black (rarely greyish brown). Persisting in the dried ears of rye.

Habitat, Cultivation and Collection: Ergot of rye is found wherever rye is cultivated and especially in regions where seed control is lax. It is more frequent in wet years than in dry years and is found especially on the edges of rye fields. Collection is at the time of harvest of the mature ears and from the threshed grain. Dried at 30-45 C (86113 'F. Cultivation is possible by artificial injection -of the closed ear of rye with a suspension in water of ergot spores. It is desirable to carry out such cultivation in areas where no other rye is being grown, although in practice neighbouring fields are not infected.

Constituents and Action: Powerfully active constituents (alkaloids and amines) that in normal medicinal doses contract blood vessels and so act as haemostatics. They stimulate contractions of the uterus. In
high doses ergot is very toxic; it can cause gangrene of the extremities, violent pains, delirium and death. In previous centuries the accidental contamination of baker's flour with ergot caused serious epidemics (St Anthony's fire, ergotism).

Usage: Because of its powerful action, ergot of rye should be prescribed only by a physician. Its principal use is in obstetrics and in neurology.