Wild Urban Plants of the Northeast

A Field Guide

By Peter del Tredici

Cornell University Press

This book is primarily a reference book that photographs and describes the multitude of plants that grow in our cities without any help from us – usually called weeds. Tredici calls them spontaneous urban plants.

Of special interest is the introduction, which challenges our “native = good, introduced = bad” assumptions. He says the notion that every city has a native flora that can be restored is absurd, given that humans have totally transformed the land on which cities have been built. He’s not talking about our carefully nurtured wetlands and protected natural areas. Rather, his interest is in the seldom-noticed plants that grow in cracks in the sidewalk, in neglected patches between buildings and roads and railway lines and in vacant industrial spaces that have been abandoned and not yet redeveloped.

Even Ailanthus altissima, or tree-of-heaven, which most of us love to hate, is given a friendly word: “Ailanthus is just as good at sequestering carbon and creating shade as our beloved native species or showy horticultural selections. Indeed, if one were to ask whether our cities would be better or worse without Ailanthus, the answer would clearly be the latter, given that the tree typically grows where few other plants can survive.”

As a field guide, this book is a wonderful aid to identification of the plants that grow uninvited all over the city, and it has lots of extra information, including the ecological function that each plant provides. Did you know that prickly lettuce (Lactuca serriola), lambsquarters (Chenopodium album) and mugwort (Artemisia vulgaris) help clean up contaminated sites by selectively storing heavy metals such as cadmium, lead, copper, zinc, chromium and nickel in their tissues?

Jane Cluver

Reprinted from Toronto Field Naturalist Nov. 2014

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