Rebuilding Earth – Plants of the Post Anthropocene

Introduction to the Weeds

The likelihood of an impoverished Earth of weeds and remnant human societies is growing stronger every day now. Human population, climate change, toxic pollution, and dwindling resources needed by living beings are all reaching points of no return. In a few years now, it will be too late to prevent global catastrophe.

My weed book will be published in the spring.  Update, March 1, 2018: A draft of the book is ready for review. Weeds of Dewey-Humboldt SCREEN RES PDF.

Here’s the introduction:

While I studied at Arizona State University, my boys and I would sometimes walk the two miles to campus to pick up assignments and visit the library. We lived just north of the Salt River, once a perennial desert stream that dams and diversions have turned into a dry riverbed. We would enter the riverbed a few blocks from our apartment and exit when we neared the campus. That hike was one of our favorite times together. The channel held scattered and flood battered Cottonwood trees, Mesquite, Seepwillow, Acacia, clusters of Squawbush, brilliant Brittlebush, thickets of Sunflowers, Mullein spikes, feathery Storksbill, curly Heliotrope, other weeds, lots of bare ground, and a million stones rounded by tumbling down the river.

Between rock throwing attacks on old tires and washing machines, we saw birds, rabbits, and lizards, but no people. During our walk down the riverbed to the urban campus of 40,000 students and thousands of staff, we never encountered another person. Not marketed for recreation and perhaps considered a wasteland unworthy of a visit, the Salt River’s dry riverbed was a strip of wilderness running through the heart of a large city.

After graduation, my research on fire ecology and historical vegetation change brought me into frequent contact with weeds. I learned that weeds are the most remarkable members of the botanical world. In a single growing season, they colonize and cover sites damaged by floods and fires. Some, such as the thistles and milkweeds spread on the lightest breeze, others have thorny seedpods that hook a ride on anything that brushes by, and some develop extensive root systems that spread and send up new shoots far from the parent plant. One weed in many D-H yards, the dainty Woodsorrel, forms tiny seedpods that explode to scatter seeds like shrapnel.

The ability of weeds to reach and thrive in damaged and inimical environments suggests that they may be the principal survivors of the annihilation of nature by human overpopulation, pollution, and climate change. This book is concerned with two questions:

  • Which weeds are present in Dewey-Humboldt (D-H) now or will be present in the future? Answering this question requires that we can identify the weeds. Drawings and descriptions of the weeds take up most of the pages. The descriptions contain answers to the second question:
  • Are the weeds of D-H valuable resources for wildlife and people? I reviewed the literature and added symbols to indicate edible and medicinal weeds (as well as the fragrant and thorny weeds).

The inspiration for the book is a fascination with the intricate shapes and dynamic features of the weeds. I warn you that there is a danger that if you look closely at these creatures, you might never turn away.

Weeds are the most dynamic members of the botanical world. The many ways they disperse their seeds and smite their competitors are often unexpected and enlightening. Weeds’ ability to colonize and thrive in damaged and hostile environments suggests that they will be the plants that survive the Anthropocene. Some weeds will make fine companions for any of us that survive, but some weeds would be inimical to humans and other animals.

Weeds evolved the ability to colonize and flourish after natural disturbances long before humans appeared. Natural selection polished the special traits of weeds for millions of years before we branched out in the primate tree and learned to herd, farm, and build. For weeds, the breaks in nature due to livestock trampling, plowing, and building are the same as natural disasters.

With increases in the number of farms, domestic animals, and climate-change driven  wildfires, and floods, the places suitable for weeds also increase. Once a small band of specialists living in the relatively tiny naturally disturbed sites, weeds have increased their numbers to become a dominant species group.

We can begin now to know our future companion plants upon which we will depend if we survive the Anthropocene.

D-H Weed Links:

The first weed is:

Weed No. 1. Alkali Heliotrope (also known as Quail’s Delight).

Alkali Heliotrope (Quail’s Delight) Heliotropium curassavicum var. oculatum. A. Pair of flower spikes. B. Young fruits. C. Fruit composed of four small brown nutlets about 1/16 inch long. D. Single nutlet. Older flowers are at the fork of the uncoiling spikes. A native perennial, the plants spread to form protective carpets over bare ground. Drawing: Lucretia Breazeale Hamilton. Copyright (c) 1972 The Arizona Board of Regents. Reproduced from Parker (1972) with permission of the University of Arizona Press.

Alkali Heliotrope (Quail’s Delight)
(Heliotropium curassavicum var. oculatum ).

Alkali Heliotrope’s tiny fragrant flowers delight bees and gnats. The uncoiling spike, a flower-studded fiddleneck, reveals little beauties pure white with yellow-green eyes that purple in sunlight. This bluish green perennial grows to about one foot, but mostly it forms flat patches of overlapping branches up to four feet wide. The plants are hairless, but lightly dusted with a white powder that easily rubs off.

A native of arid North America, Quail’s Delight can edge into a lawn or garden. Removal by pulling is a simple cure, but the plant has no thorns or burrs and you might wish to leave it on unused sites where it will protect your soil from wind and water erosion.

The plants colonize exposed alkaline or saline soils and the banks of streams and washes in arid western U. S. and Baja California. You will find similar varieties around the world. I’ve seen this one growing beside a canal in Tempe, Arizona, and a very similar variety beside limestone rocks near Fourteen Mile Creek in Oklahoma.

Alkali Heliotrope flowers. © David Eickhoff (License: CC BY 2.0)

2. Annual Bluegrass (Poa annua)

3. Annual Yellow Sweetclover (Melilotus indicus)

4. Barestem Larkspur (Delphinium scaposum)

5. Barnyard Grass (Echinochloa crus-galli)