Ustilago Maydis (Nat. Ord., Fungi), grown upon Zea Mays (Nat. Ord., Graminaceae).

Ustilago should be preserved in a dry place, and should not be kept longer than a year. This fungus is a form of smut growing upon maize.

Characters. - Irregular, globose masses, sometimes six inches (15 centimetres) thick, consisting of a blackish membrane, enclosing innumerable brownish-black, globular and nodular spores; odour and taste unpleasant.

Dose. - 1/4-1 dr. (1-4 gm.).

Action. - It resembles ergot in its action, and probably also contains the same active principles.