This year I’m ready for the prickly lettuce—not just a few, scraggly, rescued rosettes from the xeriscaped yard of my parents-in-law, but for vast, tender carpets of prickly greens, like what grows in the fields and old agricultural places on the outskirts of Denver, Colorado.
I really only discovered the merits of prickly lettuce last season. An introduced Eurasian species, prickly lettuce (Lactuca serriola syn. L. scariola) is found throughout the United States and Canada. It is distinctive in its mature form, with leaves that turn to face sideways, sometimes pointing east and west, Euell Gibbons relates in Stalking the Faraway Places (1973). Prickly lettuce leaves twist to optimize exposure to the sunlight, Sam Thayer explains in Nature’s Garden (2010); the result is a plant that looks as if it “has been pressed between two pieces of plywood.”
Mature prickly lettuce has a solid stem with deeply lobed leaves that clasp it in an alternating pattern (Weeds of the West, 2004, 9th ed.). In contrast, the margins of young leaves can have few or shallow lobes. Prickly lettuce buds and flowers are numerous, borne in a panicle or branched cluster of beaked buds that open into small, yellow ray flowers. Later, the seedheads look a bit like dry, dandelion seed puffs.
I’d chased edible wild plants for years before paying much attention to prickly lettuce. I knew from the guidebooks that it was edible—but also that it possessed an extremely bitter latex coursing through stems and petioles and covering the mature leaves. Furthermore, as it bears thin, needle-like bristles on the leaf margins and midveins, I figured it would probably not be very fun to eat.
A few years ago I tasted a mature leaf despite my misgivings at Colorado forager Cattail Bob Seebeck’s house, only to discover that it was indeed too bitter to eat. Still, a forager in Colorado is a desperate forager indeed, for her warm seasons are short and the pickings slim compared to other regions.
So last spring, hungry for green forage in April, I experienced a brief love affair with the scraggly yard rosettes of prickly lettuce in Gregg’s parents’ backyard in Aurora on Denver’s outskirts. It was early enough in spring that they had not yet sprayed the unwanted Asteraceae with yard poisons, so they invited me to scavenge what I could.
The specimens were still in their young, spring rosette forms, but the latex in the dandelion-like leaves and small prickles in a line along the underside of the leaf midvein helped to confirm that I’d found prickly lettuce.
Lettuces are members of the Aster or Sunflower family (Asteraceae), the second largest family of flowering plants, which worldwide includes about 920 genera and 19,000 species (Elpel, 2013). Within that there are a number of tribes, including Lactuceae— the lettuce tribe, whose members have strap-shaped flower petals and milky or colored sap.
Within Lactuceae, Thayer (2010) identifies seven genera as the most common, widespread, and useful wild food plants: Cichorium (chicory), Hypochaeris (cat’s ear), Lactuca (lettuce), Prenanthes (white lettuce), Sonchus (sow thistle), Taraxacum (dandelion), and Tragopogon (salsify). He calls these the “lettuce-dandelion” group. Once you know you have a member of the lettuce-dandelion group, his dichotomous key in Nature’s Garden (2010) is useful for figuring out which genus it is while the plants are still young, since the key focuses on leaf and stem features rather than relying on buds, flowers, and seeds.
Among the distinguishing Lactuca or lettuce features I found on the young rosettes, based on the key, were leaves with “toothed, lobed, or with wavy or irregular margins,” leaf midribs that were triangular in cross section “forming a sharp or nearly sharp keel,” white or light brown latex, and “erect hairs or spines found along the keeled bottom on midvein” (present in all Lactucas except L. muralis).
In the youngest specimens, however, I had to cut and squeeze the midveins well in order to spy just a hint of the latex, which becomes more plentiful as the plant matures.
I rinsed and chopped and tasted one. The prickles had not yet firmed up enough to be bothersome, and the flavor was far less offensive than the mature plant I’d tried at Cattail Bob’s, though it was still bitter like a dandelion.
This makes sense because dandelions and chicory belong to the lettuce tribe too. All members, including wild lettuces, contain a bitter, milky sap. Despite the modern aversion to bitter foods, this milky juice is valuable as a digestive aid and spring tonic, useful for cleansing the liver after a long winter of eating hard-to-digest foods, Elpel writes in Botany in a Day (2013 ed.). So the fact that young prickly lettuce is a touch bitter can be considered a good thing—both for those who enjoy bitter greens like endive, and for those who relish tapping into the wisdom of our refrigerator-less forbears who enjoyed annual health benefits from the bitter greens of spring.
There are 12 species of Lactuca in North America—all edible, Thayer writes, though they vary in palatability. He says L. canadensis or “good lettuce” is the best to use for food, and also describes L. biennis, or “bitter lettuce” in his account. Both are native and neither is prickly.
In Colorado’s Front Range, Weber & Wittmann distinguish prickly lettuce (L. serriola), a disturbed area-loving annual, from other Lactucas based on the presence of spiny-margined leaves, and spines along the midrib and veins (Colorado Flora, 2012 ed.).
But the West is also home to the native Western lettuce (L. ludoviciana), a biennial reported by Rydberg (1905) to occur in Denver. This lettuce may also appear spiny along the margins—distinguishing it from non-prickly lettuces like L. muralis, L. canadensis, L. biennis, and L. pulchella. But the margins of Western lettuce have teeth with points, compared to prickly lettuce’s “nonvascular, hardened, non-tapering projections well beyond the photosynthetic surface,” Thayer explained when I wrote for clarification (personal communication, 2014).
The upshot is that I spent a long time questioning whether all the “prickly” Lactucas I was eating were the same species. One of the distinguishing factors is how the leaves react to the sun, since Thayer also notes that the leaves of L. ludoviciana do not twist in the sun, whereas those of L. serriola do.
The native Lactuca ludoviciana is found throughout the West, starting in western Kentucky and Indiana, though it is federally protected in Indiana and should not be foraged there (USDA). According to Daniel Moerman’s database of ethnobotanical resources at the University of Michigan-Dearborn (http://naeb.brit.org), leaves of L. ludoviciana were eaten by the Gosiute people of Utah (Chamberlin, 1911), and the Cherokee cooked and ate L. canadensis leaves as greens (Hamel & Chiltoskey, 1975). Lactucas also served medicinal purposes among native groups, with recorded usage as sleep inducers, stimulants, treatments for gastroenteritis, pain-killers, and lactation inducers, among others.
The West is also home to blue lettuce (Lactuca pulchella syn. L. tatarica), a non-spiny species with lance-shaped or linear leaves and blue-purple flowers.
Cultivating the Wild
Interestingly, our modern lettuces—like iceberg, Romaine, butter, green leaf lettuce, and stem lettuce or celtuce—are cultivars of Lactuca sativa, thought to have been bred from prickly lettuce (L. serriola) thousands of years ago in Egypt.
To this day, prickly lettuce hybridizes with cultivated lettuces, though the resultant seeds from interbreeding apparently produce tough, bitter leaves. The good news is that because of its interest in cross-breeding, prickly lettuce can help diversify the gene pool, protecting lettuces in perpetuity.
Forager on a Bed of Lettuce
Last spring, around the same time I was experimenting with my first scraggly lettuce rosettes in Aurora, I started noticing lush patches of a young green I did not know. I photographed and wondered about these lovely patches, only to later discover that they, too, were wild lettuces with prickly margins and midveins and latex that became more copious later—just growing under different conditions than the tough, solitary invaders of my father-in-law’s carefully tended landscape.
Once I made the connection I started picking light green rosettes where the leaves looked healthiest—some from forested areas with dappled sunlight and others from open fields in direct sunlight. Some of the young lettuce I picked had the distinctly twisting leaves and deep lobes of prickly lettuce, whereas other young specimens were less lobed and not so obviously turned.
Back at the house, I swirled the leaves in a bowl of cold water to refresh them, followed by a forceful spraying with the faucet. They damaged more easily than the mustard greens I’d also been collecting, but not too badly after their two-hour journey back to the high country. Because some of the greens I collected were a little too close to a dog-walking zone for comfort, I soaked them in a water-and-vinegar bath in the hopes of killing any unwanted microbes.
Last spring’s lettuce greens went a long way into dinner salads, pack-along salads, and spring rolls. This summer I also hope to try them in the style of the ancient Romans, poached with a warm oil-and-vinegar dressing poured overtop.
Warm Welcome & Fond Farewell
The lettuce beds turned out to be the gift that kept on giving, for they lasted—fresh, green, and unbolted—into summer. Then, to my pleasant surprise, they reawakened again in fall. My friend Butter wrote to tell me about it. “I can’t believe I never noticed them in fall before,” she said. “I must have been too busy with my head turned to the sky, looking at the fruit in the trees.” Since they were still going strong in late November last year, I headed down for a last wild food mission of the season. We got prickly wild lettuce and prickly pears on those last few sunny days before the weather changed and my world turned white once more.
In retrospect it’s funny to have spurned a plant for so many years, only to be suddenly reawakened to its merits. As my joy over wild lettuce grows with each new epiphany, I find myself eagerly awaiting those small miracles still in store. Though I have been intimate with it now for only one season, wild lettuce seems a fitting way to put foraging to bed each season, and to welcome spring once more.