Whenever I encounter New York's native cactus, the eastern prickly pear, I pause. It's weird to see something that is both instantly recognizable and completely out of step with the rest of the city's ecological character.
What on earth," I always want to ask, "are you doing all the way up here?"
But prickly pears are no recent arrivistes. Unlike, say, the gingko trees that the City has planted on sidewalks in every borough, Opuntia humifusawas here long before the Europeans came. Its success is the result of a bold leap northward—a journey made by some pioneering cactus fragment or seed long in the past, probably soon after the Wisconsin Ice Sheet began to recede from New York City some 25,000 years ago. It washed up, or was carried by an animal, and spread its shallow roots in our little corner of the country.
Lenape Native Americans ate the cactus fruits, and used the pads as a compress for throat ailments. Local animals know they're good to eat, too. In the fall, its waxy red fruits provide food for deer, eastern cottontail rabbits, and box turtles. In the spring, it produces gorgeous yellow flowers—a boon for native bees and flies searching for pollen and nectar.
Some plants and animals seem to thrive in New York City because of the human presence—peregrine falcons, for example, nest on and hunt from the high ledges of our skyscrapers and bridges, and raccoons climb through our alleyways and even fire escapes in search of trash to eat. The eastern prickly pear—a low-growing, easily trampled cactus—is in a second category: the downtrodden native species, hanging on by a root.
"The thing that intrigues me the most," said Nancy Slowik, a naturalist at the New York Botanical Garden who specializes in native plants, "is how they're capable of surviving in these colder and wetter environments."
Slowik co-founded the city's first native plant project, the Greenbelt Native Plant Center, on Staten Island. Throughout her long career as a naturalist, she's worked in many of the places around the city where prickly pears tend to grow, including the Gateway National Recreation Area in Staten Island, where she began her career, and Greenbrook Sanctuary in the Palisades, where she served as director for 20 years. Today, she teaches at the New York Botanical Garden in the Bronx, and coordinates their urban naturalist program.
"I've become really interested in urban flora, and I teach a class called 'Growing Between the Cracks' about the plants that are able to survive in parking lots and places like that—really extreme conditions," she explained. "When I compare them to plants that grow in the rocky outcrops of the palisades, many of them are similar."
The eastern prickly pear favors rocky terrain on ridges and summits and dry, sandy soils. It does well in desolate maritime areas and on cliff faces or outcroppings on hillsides. Like all cactuses, it has a shallow, expansive root system called a mat that allows it to quickly absorb water out of the surface of the soil it's rooted in. Like many New Yorkers, its success depends on real estate.
"It's location, location, location," Slowik said. "The prickly pear has found this niche in these not quite extreme but borderline extreme habitats. These are places where fragile plants that need more water, need more soil, cannot survive."
Looking at any cactus, the enormous evolutionary pressures of desert landscapes are apparent at a glance. The plants have waxy, succulent bodies, or stems, designed to store and retain water in an environment where it might not appear for months. Their spines serve, among other purposes, to protect that precious cargo from the desert's ecosystem of scarcity.
"The main adaptation," Slowik noted, "is that the spines are modified leaves. It always blows my mind. In the desert, you don't want to have these broad, flat leaves that trees or other plants have because you're going to lose your moisture. The spines are designed to reduce loss of water to transpiration."
New York's wilds aren’t the sun-scorched landscapes that cactuses evolved to withstand, but eastern prickly pears have found pockets of the city where they can get by just fine. I've seen them in southern Brooklyn and Queens, nestled into dry, nutrient deficient spits of sand near Jamaica Bay and the ocean, as well as on treeless rock protrusions in the Bronx.
"These are extremely dry habitats," Slowik explained. "They're not deserts, but they're similar. They're exposed to the elements."
None of us can look our best all the time, and unsurprisingly, eastern prickly pears aren't quite as charismatic during New York City's colder months. In mid-winter, when deciduous trees throughout the northeast are leafless, prickly pear cactus pads lose a good deal of their water and take on what Slowik described as a "sort of desiccated" appearance. Indeed, by February, the plant looks pretty fucked up and stepped-on—about as alive-seeming as the plastic bags that sometimes get snaredaround them.
In addition to seeking out little patches of desert in the city, the eastern prickly pear has a few tricks to ride out our long, cold winters. The first is simply to lay low. Eastern prickly pears in the southern United States have been recorded to grow to nearly seven feet tall, but up here in the freezing northeast, Opuntia humifusa doesn't get much taller than a foot and a half. It survives by hunching over, out of the way of wind and weather. Its second line of defense is a more complex chemical innovation—cellular glucose that prevents its cells from exploding, like soda cans left in the freezer, during cold spells.
While by cactus standards, the eastern prickly pear is practically an arctic explorer, it's not the world's northernmost cactus. That distinction belongs to Opuntia fragilis, the little prickly pear—a diminutive cousin of the eastern prickly pear that maxes out at around four inches tall and can be found all the way up in British Columbia.
Russell Jacobs is a writer, environmental educator, fisherman, birder, and all-around nature guy from New York City. His writing is focused on the ecologies of urban environments, and has appeared in Slate, Urban Omnibus, the Rockaway Wave, and the Rockaway Times.