The good, the bad, and the deadly of plants
When British soldiers arrived in Jamestown in 1676 to quell a Colonial rebellion, a few daring farmers slipped some jimson weed into the British chow. The soldiers hallucinated for 11 days. "One would blow up a feather in the air," writes a historian, "another would dart straws at it with much fury; and another, stark naked, was sitting up in a corner like a monkey."
Jimson weed, properly known as Datura stramonium, is a member of the nightshade family (think potatoes, petunias, and paprika). Evolution has given nightshades, and so many other plant families, a formidable arsenal of chemical defenses. Some of the most fascinating of these are described in "Wicked Plants: The Weed that Killed Lincoln's Mother and Other Botanical Atrocities," by writer and gardener Amy Stewart.
"Thirty-nine hundred people are injured annually by electrical outlets while 68,847 are poisoned by plants," Stewart notes in her introduction, and then delivers her who's who of fearsome flora. There's ayahuasca tea, which makes imbibers see "dragons spitting fire"; Johnson grass, whose immature shoots contain enough cyanide to kill a horse; and peacock flower, the seeds of which West Indian slaves ate to abort pregnancies, both to spare their children a life of slavery and to avoid adding to their owners' wealth.
There's not a lot of meaty text in "Wicked Plants," but Stewart is so good, as in her previous books, at cutting straight to the most interesting stuff, whether it's about Freud's cocaine use ("In the last few days I have felt quite unbelievably well," he wrote to a colleague in 1895) or the coyotillo berry, whose toxic agents can sit in your system for a week before total paralysis sets in.
Many of the plants in your garden and grocery store turn out to have dark sides, too: cashews, peppers, azaleas, bleeding hearts, lobelia, and tulips, to name a few.
A less unsettling and more substantial new plant book is "An Orchard Invisible: A Natural History of Seeds," by Jonathan Silvertown, a professor of ecology at Open University, a distance-learning school in the United Kingdom.
I loved this little book. In his first two chapters Silvertown's prose gets a little thorny with botanical language, but don't lose heart, because "An Orchard Invisible" practically spills over with interesting insights. A chapter on the evolutionary rationale for fruit becomes a meditation on color perception. In one paragraph Silvertown will tell you about how plant poisons affect different populations of people, and in the next you're learning that Pythagoras didn't eat beans. A discussion of seed dispersal begins with a note about paper airplane design. His chapters on beer and coffee are particularly enthralling.
"The story of seeds, in a nutshell, is a tale of evolution bursting with questions," writes Silvertown, and essentially "An Orchard Invisible" is an exploration of plant evolution, a path he describes as "always blindly turning corners, reversing fortunes, and springing surprises." Orchid seeds are smaller than grains of salt and coco de mer palm seeds are big as beach balls, and in between Silvertown finds a hundred opportunities to ask why. Why do seeds germinate when they do? Why do some plants reproduce asexually? Why do oaks vary seed production from year to year?
It's spring, after all, and pretty much every living thing around us is racing against time and temperature to meet their evolutionary imperative: reproduction. As Silvertown points out, "Seeds are the products of sex."
Which brings us to the season of all that propagation: summer. "The main order of business in summer is reproduction" writes Bernd Heinrich, a biology professor at the University of Vermont, in another new book, "Summer World: A Season of Bounty." Heinrich embarks on a project of paying attention, in this case, to a clearing in the woods outside his cabin in Maine as it comes to life repeatedly over the course of several summers.
This is hands-and-knees science at its most engaging. Heinrich is an experimenter and a meddler. He'll drop tadpoles into aquariums of fish, stuff a wasp nest into his crow aviary, and cut and triple-bag branches of hazel and alder to see whether they will flower in darkness. He'll perch on a tree limb for hours, watching birds come and go, or put trash cans over his crocuses to see whether they open at a different temperature in the dark.
Out in the worlds that are our backyards, Heinrich finds much of the violence and drama that Charles Darwin found. "For each of the large animals," Heinrich writes, "there are necessarily also hundreds or thousands of deaths of smaller ones of other species that get eaten to produce this life. And every one of them has evolved mechanisms to reduce its chances of getting eaten."
Anyone who wants to feel more engaged with the trees, bugs, and birds of summer should enjoy "Summer World." Heinrich sees so much, and yet admits, "There is much right under my nose that I don't see, and thus I look forward to getting out, again and again - to discovering."
As the birds return, and the trees repeat the abiding cycle of leafing out, as the great greening occurs all around us, we can only hope to see half as much as Heinrich does.
Anthony Doerr is the author of "The Shell Collector," "About Grace," and "Four Seasons in Rome." 
