mould

a fine soft green, grey or black substance like fur that grows on old food or on objects that are left in warm wet air รา, เชื้อรา

Her worst problem was mould growing on all the walls and many other surfaces.

Once the house is cleaned and sanitised, damp smells caused by mould should also go away once the spores are removed from the house.

A mould type of growth had taken over anything that wasn't under water.