Ergot

Tom is culturing ergot.

Source: tatoeba (12328754)

Ergot first appeared on the stage of history in the early Middle Ages, as the cause of outbreaks of mass poisonings affecting thousands of persons at a time. The illness, whose connection with ergot was for a long time obscure, appeared in two characteristic forms, one gangrenous (ergotismus gangraenosus) and the other convulsive (ergotismus convulsivus).

Source: wiktionary

Since the text was in type, Mr. R. I. Pocock has pointed out (The Field, Jan. 20, 1912, p. 143) that the aperture of a scent-gland situated on the posterior aspect of the hind-foot of the Indian rhinoceros occupies a position very nearly similar to that of the ergot in the foot of the horse (infra, p. 41).

Source: wiktionary

It is crossed medially and laterally by the ligament of the ergot (not shown), that, subcutaneously, connects the ergot with the hoof cartilage.

Source: wiktionary