Vinegar-plant

Vinegar-plant (Penicillium glaucum), a fungus of the sub-order Hyphomycetes, but somewhat resembling those known by the name of Mould (q.v.). It forms a flocculent mass or web, which is tough and crust-like or leathery, and when examined by the microscope is seen to consist of a mycelium of branched threads, with the branches somewhat tangled, and the spores disposed in patches about the pencil-shaped ends of fertile threads. It is found on decaying bodies and in fluids undergoing the acetous fermentation, which it greatly promotes, and indeed readily occasions, a small piece placed in sugar and water soon changing it into vinegar. Advantage is sometimes taken of this property for making vinegar.