Fortunately I had a copy of the booklet "Wildflowers of Algonquin Provincial Park" and it provided the answer:
      The "fungus" turned out to be the "Indian Pipe" plant. A ghostly single-stalked, single-flowered, all-white, plant with a single downward drooping bell-shaped flower (also white). It stood about six inches tall on the shaded forest floor among the dead leaves. As the days passed the flowers turned black and the plants withered away. I expected to see more of them in the same place in the following years but unfortunately none appeared - Ghosts are like that!

      This is the kind of plant that "once-seen-never-forgotten". It's unique in that it has no chlorophyll and thus its "ghostly" whiteness and the various other names ascribed to it in the references.

      I have not studied this plant in any detail. When I decided to add it to the website I was certainly impressed by the number of references I found on the web, and so I am simply going to enumerate a number of them here for you to explore at your leisure. When you've finished you will certainly be able to identify this plant. From the locales of the references, the plant is widespread and should be present in some of Toronto's parks. The references cover many other wildflowers, so if you are interested in the subject, explore!