saprophytically

Bladesover they cannot replace it; they just happen to break out over it -- saprophytically.

Tono Bungay 1906

Such a grouping is not always entirely satisfactory, for many of the kinds that live saprophytically under normal conditions may become parasitic if opportunity offers, and also many of those that are usually regarded as parasitic may be grown in cultures of agar or other media, under which conditions they may be regarded as living saprophytically.

Insects and Diseases A Popular Account of the Way in Which Insects may Spread or Cause some of our Common Diseases Rennie Wilbur Doane