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The Native Plants of the Quiroste Valley

by Sue Rosenthal on April 01, 2016

(clockwise from top left) Coast redwood (Ivan Sohrakoff, isophotographic.com), wild cucumber (Margo Bors,  margobors.com), tanoak (Bill and Wilma Follette), cow clover (Tom Ballinger).
(clockwise from top left) Coast redwood (Ivan Sohrakoff, isophotographic.com), wild cucumber (Margo Bors, margobors.com), tanoak (Bill and Wilma Follette), cow clover (Tom Ballinger).

Coast Redwood (Sequoia sempervirens)

Current research suggests that Indians have lived in California for at least 13,500 years. Over that time the region’s climate has changed, as have the ranges of many plants they used. Today we think of coast redwood as a central and northern California tree, but redwood bark fossils found in excavations in Los Angeles indicate that it grew in canyons of the Santa Monica Mountains 40,000—and perhaps as recently as 10,000—years ago.

Fossils of the earliest redwood ancestors on the planet are more than 200 million years old. Sixty-five million years ago, milder temperatures, higher humidity and more even distribution of rainfall throughout the year allowed early redwoods to grow across North America as well as in Greenland, western Europe, and Asia. But the global climate cooled, and redwoods disappeared from all but western North America, separating about 36 million years ago into the two California species we know today, coast redwood (Sequoia sempervirens) and giant sequoia (Sequoiadendron giganteum). As California’s climate became drier, the moisture-loving Sequoia sempervirens was restricted to coastal areas, and then eventually to a narrow belt approximately 450 miles long from southwestern Oregon to southern Monterey County.

California Indians living in the northern portions of the redwood’s range used slabs of its bark to weave skirts and construct houses, and fallen logs to make dugout canoes hollowed with fire and shell or stone tools. Redwood burl shoots appear in basketry, and because they expand when wet are said to be especially good for cooking baskets. At the Quiroste Valley Cultural Preserve, archaeological studies have found redwood to be the most common fuel.

In 1909, renowned California botanist Willis Linn Jepson predicted the future of the coast redwood: “At the present rate of cutting the last of the virgin forests will be milled within forty five years…” Today, of the two million acres of old-growth redwood forest that existed before commercial logging began in the 1850s, just five percent survives.

Clover (Trifolium species)

Clovers are herbaceous flowering plants that are short in stature, often just a couple of inches high, but large in importance both for native Californians and for the ecosystems in which the plants grow. For California Indians, seasonal greens like clovers were highly valued foods and were managed carefully to assure continued abundance. Throughout California, clovers were among the most commonly eaten greens.

While it’s possible to identify clover seeds in plant material found in archaeological sites, determining the actual species can be difficult, so it’s not known which clover species were used by the Quiroste people. But we do know that today two species—cow clover (Trifolium wormskioldii) and pinpoint clover (T. gracilentum)—grow in the area. Both have low-growing succulent stems and creeping roots that eventually form masses topped by magenta-pink flowers, and both generally prefer open moist places.

Traditionally, in coastal areas like Quiroste, clovers were harvested and eaten fresh after the rains began. Often they were eaten on the spot: pulled up in handfuls, rolled into balls and eaten with or without salt, sometimes accompanied by cakes made from bay laurel seeds (peppernuts).

Like many other landscapes of importance to California Indians, clover fields were managed by burning after the plants had dropped their seeds. This disturbance stimulated growth and also enriched the soil by releasing nitrogen stored in the plants. Although nitrogen is essential for plant growth, the abundant nitrogen in our atmosphere is unusable by plants in its gaseous form; they can only use nitrogen in the form of ammonia. Fortunately, certain soil bacteria can convert atmospheric nitrogen to ammonia through a process called nitrogen fixation. These bacteria form partnerships with many plants in the pea family, including clovers, by invading their roots and creating nodules where they produce ammonia that can be absorbed by the plant. For its contribution, the plant supplies nutrients and energy to power the bacteria. Almost all of the fixed nitrogen goes into the plant, but it’s returned to the soil and the ecosystem when the plant dies and decomposes.

Wild Cucumber (Marah fabacea)

Recognizing toxic plants is not only essential for avoidance and survival, but can also be useful for wellbeing and sustenance. California Indians knew their habitat and knew how to put many poisonous plants to productive use. Some were used as medicines, some were harvested for their toxic properties, and some, like wild cucumber, were used for both (sometimes the difference between a poison and a medicine is just a matter of dose.

Wild cucumber is indeed a wild member of the cucumber family. Like many of its domesticated relatives, it has a fleshy, rounded, greenish fruit, but the outside of wild cucumber’s fruit is covered with prickles and the whole thing is somewhat poisonous so was never consumed as food. Also like its relatives, it takes the form of a scrambling non-woody vine that emerges and grows quickly with the rains and then dies back to the ground after fruiting in early summer. But underground is its storehouse of energy, a broad root that over time can weigh more than 100 pounds and attain a length of a few feet. Sometimes the root divides, taking the rough form of a person and earning the plant common names like “manroot” and “old man in the ground.”

All parts of wild cucumber are poisonous, but the root contains the highest concentrations of its toxic compounds, cucurbitacin and megharrhin. The mashed root tossed in quantity into small pools and slow streams caused fish to float to the surface, where Indian fishermen quickly scooped them up. Fish caught in this way were small to medium sized, like trout and lampreys, and were not toxic to eat. Although fishing with poisons like wild cucumber is illegal today, as traditionally practiced by California Indians in times of greater abundance, it was a simple and efficient way to catch many fish at once and assure provisions for a group.

Tanoak (Notholithocarpus densiflorus)

Among the traditional plant foods eaten by native peoples in the California region, the most widely consumed and nutritionally important was acorn, the protein-, fat-, and complex carbohydrate-rich nut of the oak tree. Yet one of the most prized acorns comes not from any of California’s 20 species of true oaks (genus Quercus), but from the tanoak tree, in the related but separate Notholithocarpus genus within the oak family.

Indigenous Californians valued tanoak acorns for their flavor. However, like all acorns, those of the tanoak contain high levels of tannin compounds and are unpalatable unless processed. Traditional methods of preparing acorns removed the tannins: shelled acorns were pounded into fine meal in a stone mortar and then leached in a sand basin with water poured through until the bitterness was gone. In a cooking basket with water and heated rocks, acorn meal could be made into thin soup or thick porridge; on top of hot rocks or in an earth (pit) oven, moistened meal could become cakes or bread.

California Indians used tanoak sustainably for thousands of years. But in the mid-1800s settlers from the eastern U.S. began exploiting the tree for the tannins in its bark in the production of durable, heavy leather for items like saddles, travel trunks, and machine belts (tannin, tanning, tanoak). Loggers cut down the trees and stripped off the bark, usually leaving the rest to rot on the forest floor. By the late 1800s, tanoak-cured leather predominated throughout the U.S., and the trees were exploited at such a high rate that the supply was depleted and the industry all but collapsed in the 1920s.

Yet tanoak is a hardy tree and populations rebounded when bark harvesting slowed. But a new attack on the species began just a few decades later. As a stump-sprouting, fast-growing hardwood in the redwood, Douglas fir, and mixed evergreen forests of the Cascade and Coast ranges from southern Oregon to Santa Barbara, tanoak is considered a weed by industrial foresters harvesting the more commercially desirable conifers. Since the late 1940s, logging companies have used herbicides to kill tanoaks in order to reduce competition with young redwoods and Douglas firs.

And an even newer human-mediated assault could cause the tanoak’s complete extinction: sudden oak death. Of all the California native plants affected by SOD, tanoak is the most susceptible, and more than a million have died in the 20 years since SOD made its way here on nursery plants. But unlike the previous threats, SOD has galvanized concern among forest professionals and concerned citizens for preserving and once again valuing this beautiful and bountiful tree.

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