Chapters 4-10, Summary and Analysis

Only seven hundred of the world's three hundred thousand species of plans have caused death or serious illness to those in the western hemisphere. Yellowstone has only two. They are water hemlock and Death Camas. Two or three deaths have come from water hemlock. Six deadly poisonous mushrooms grow in Yellowstone as well, such as the Death Cap, Destroying Angel, Deadly Concybe, Deadly Cort, Deadly Galerina, and the Conifer False Model. Deaths occur due to kidney or liver failures and all six have caused deaths. There is no evidence of mushroom fatalities that can be verified in the park.

The Water hemlock is dangerous because it looks like an edible wild parsnip and carrot. When eaten, it affects the nervous system, causing convulsions and usually death. Whittlesey then tells several of the relevant stories, such as that of Keith...