According to the Wikipedia article manchineel actually hasn't killed anyone in modern literature, despite having a description of the taste of it's fruit. My guess is the tree doesn't directly kill as much as massively inflame flesh so it's still "survivable"
"Spotted water hemlock grows in freshwater marshy or swampy areas throughout the entire continent of North America, save the island of Newfoundland. It can be found in Alaska and Florida, in the vast unpopulated stretches of the American west and in the parks of New York City. It is not especially common, but its range is massive."
