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A Tale of Specimens Lost and Found

Many of the plants first collected by these trailblazing explorers grace American gardens today.

Led by CaptAIns Meriwether Lewis and William Clark, 40-odd rough-and-ready volunteers known as "The Corps of Discovery" crossed the uncharted wilderness of the American West in the early years of the 19th century with the principal aim of finding a water route to the Pacific Ocean. Lewis and Clark were resourceful men who possessed a critical blend of military and frontier experience but precious little training in botany. Yet part of their mission, as outlined by then-President Thomas Jefferson, was to observe plants growing in the regions through which they traveled-especially those not known at that time by the American scientific community-and to return with specimens.

Despite Lewis and Clark's relative botanical inexperience, the plant collections they made on the expedition rank among the most significant in North American history. All of the collections were made between 1804 and 1806, from the area that is now Missouri, Kansas, Iowa, Nebraska, North and South Dakota, Montana, Idaho, Oregon, and Washington-regions previously untapped by botanists. They brought back more than 200 different kinds of plants, including about 80 species new to science and three entirely new genera. The plants represent the flora of vastly different habitats, ranging from prairie to desert, mountain, river valley, and ocean shore. Although other, more botanically trained plant explorers followed their trail west, Lewis and Clark were the first Americans to record the natural diversity and wealth of the region.

The firsthand accounts of their explorations of the West, recorded in detailed journals by the captains and other members of the corps, miraculously survived the hazards of the trail and have fired our national imagination for nearly 200 years. The story has been recounted and interpreted in numerous books, magazines, films, poems, sculptures, and paintings.

Such rich documentation does not, unfortunately, exist for the post-expedition analysis of plants that the explorers brought back (see below). But by piecing together what has been preserved and considering the value of these plants in our gardens today, we can gain an appreciation for the magnitude of their discoveries.

The Journey

Jefferson had long dreamed of an exploration of the territory west of the Mississippi River, and it had been a topic of discussion among members of the American Philosophical Society-an organization founded in 1743 by Benjamin Franklin-for many years. As president, Jefferson convinced Congress to appropriate the $2,500 considered necessary to fund the expedition and selected his personal secretary, Meriwether Lewis, to lead it. Lewis, in turn, asked his longtime friend William Clark to serve as co-commander. Both were proven military officers, selected for their frontier experience, knowledge of the woods, and familiarity with Native Americans.

Although neither captain was a trained botanist, Lewis in particular was a keen observer of nature who had developed an early interest in plants. His mother, Lucy Marks, a respected healer in Albemarle County, Virginia, cultivated and collected plants that she used for ministering to neighbors and relatives. While growing up, Lewis learned to identify indigenous species and became familiar with their medicinal applications. This knowledge served him well on the trail.

Jefferson sent Lewis to Philadelphia in the spring of 1803 to acquire supplies and to be tutored in various scientific skills Jefferson considered necessary for the success of the expedition. Lewis took a crash course in botany-including how to preserve plant specimens-from Benjamin Smith Barton, a professor at the University of Pennsylvania. Lewis took a copy of Barton's Elements of Botany, the first botanical textbook published in America, with him on the journey.

After assembling in St. Louis, the expedition departed on May 4, 1804, following the course of the Missouri River, first due west and then northwest. Lewis and Clark divided their responsibilities according to their experience and abilities: Clark was the primary cartographer, while Lewis was the naturalist-he collected nearly all the plant specimens. When traveling by water, Clark, the more experienced riverman, commonly assumed responsibility for the boat, while Lewis walked on shore, recording his observations about the land and collecting whatever specimens he found interesting.

The corps constructed its first winter's quarters at Fort Mandan, near present-day Bismarck, North Dakota. Local Indians acquainted the explorers with a variety of uses for many of the native plants. In the spring of 1805, Lewis and Clark sent Jefferson 67 plant specimens they had collected on their journey up the Missouri River along with their journals, maps, animal specimens, and Indian artifacts collected to date. Jefferson received them in August of the same year, and after examining the plant specimens, sent them to Barton in Philadelphia for study.

The explorers proceeded westward along the Missouri River. They constructed two caches for the specimens collected between Fort Mandan and Camp Fortunate, near what is today Dillon, Montana, which they planned to retrieve on their return. Unfortunately, flooding and rot destroyed all but one of these specimens. After a difficult crossing of the Rocky Mountains, they reached the Pacific Ocean in November 1805 and spent the winter of 1805-1806 at Fort Clatsop, quarters they built near present-day Astoria, Oregon. This location proved to be particularly rich in unfamiliar flora.

On their return trip, Lewis and Clark continued their observations and collections, encountering some of the same plants they saw when they were traveling west, but now in a different season. The corps returned to St. Louis on September 23, 1806, laden with artifacts, specimens, journals, and tales that documented their 6,000-mile journey.

Unforeseen Obstacles

Events, however, conspired to reduce the immediate impact of their botanical discoveries. When the caches along the Missouri River flooded, their preserved specimens and packets of carefully collected seeds were lost, significantly reducing their introductions from that region.

Later explorers found the area rich in new species. Both Thomas Nuttall and John Bradbury ascended the Missouri River in 1811, returning with most of the same species collected by Lewis, and many more as well. "Nuttall had seeds of his species available for sale in Fraser's Nursery in London, England, by midsummer of 1813," explains botanist James Reveal of the Norton-Brown Herbarium at the University of Maryland.

Jefferson looked to scholars and friends to assess the garden and scientific value of the specimens and seeds Lewis and Clark brought back, but recorded details of their distribution are sketchy. He offered some of the seeds to a couple of longtime gardening correspondents with whom he exchanged both seed and plant information. Letters record Jefferson's intent to provide seeds to André Thoüin, director of the French National Garden, and to a Madame de Tessé. Seeds were probably sent to other notable horticulturists of the day, and Jefferson kept a few for his own gardens, including an ear of Mandan corn Lewis had sent him from the Missouri River Valley. Jefferson had long been experimenting with various strains of corn and particularly prized this one.

The majority of the collected seeds were divided between two Philadelphia plantsmen: Bernard M'Mahon, who owned a seed store on Market Street, where some speculate the original plans for the journey were hatched; and William Hamilton, who owned the Woodlands, a 300-acre estate renowned for its plant collections and landscaping. Hamilton, who had assisted Jefferson in his landscape plans for Monticello, received seeds from both the shipment from Fort Mandan and those that returned with the explorers.

But American efforts to introduce plants from the West in the early 19th century were limited. A few new plants from the Lewis and Clark collections were offered commercially, but many were found to be unsuited to the eastern climate. For the most part, the plants introduced into cultivation, though originally described by Lewis and Clark, were derived from the collections of subsequent explorers. "Into the vacuum came...the Scot collector David Douglas with the Royal Horticultural Society," says Reveal. "It would be Douglas in the mid- to late 1820s who would introduce Lewis and Clark discoveries into the garden." And because definitive classification of the plants was several years coming-and publication of Lewis and Clark's findings was so long delayed-"the true results of Lewis and Clark's expedition were not fully understood until a century later," says Reveal.

Among the many plants Lewis and Clark first described and collected are towering trees, ornamental and fruit-bearing shrubs, herbaceous perennials, annuals, and bulbs. Some became popular in the 19th century. Others have gained favor in more recent years as rock garden specimens or meadow wildflowers. With the resurgence of interest in native plants, it is likely that more may be made available to gardeners in the coming years.

The Plants

One of the first plants from the expedition to gain acclaim was Oregon grape holly (Mahonia aquifolium, formerly Berberis aquifolium), an ornamental shrub that caused quite a stir when M'Mahon introduced it. Its evergreen habit, bright yellow spring blooms, and grapelike clusters of blue-black berries made it a shrub much sought after for early 19th-century gardens. Hardy from USDA Zones 5 to 9 and heat tolerant in AHS Zones 9 to 3, it grows best in moist, well-drained soil with some shade. It remains popular as a foundation plant and shade garden specimen.

With its thorny young growth, the deciduous Osage orange (Maclura pomifera) gained popularity as a barrier hedge soon after it was introduced, and its decay-

resistant wood made durable fence posts. A fast grower, it typically attains a height of 20 to 40 feet with an equivalent spread (Zones 5-9, 9-4). At St. Peter's Episcopal Church on Pine Street in Philadelphia, a row of stately osage orange trees nearly 200 years old shades the churchyard. It is widely believed that these trees were grown from seeds or cuttings Lewis gave to Bernard M'Mahon.

The Saskatoon serviceberry (Amelanchier alnifolia, Zones 4-9, 8-3), generally develops as a multi-stemmed shrub to 18 feet tall. Its blue-purple berries, which ripen in early summer, were a food source for the Plains Indians, who combined the dried berries with buffalo meat to make pemmican, a food they put by for winter.

The fruit of the snowberry (Symphoricarpos albus) is white, and its rounded deciduous leaves are a soft, blue-green. It grows three to six feet tall and wide and is particularly valuable in shade gardens. M'Mahon successfully propagated it from seeds Jefferson sent, and by 1834 snowberries were reported to be growing in many gardens around Philadelphia. (Zones 3-7, 7-1.)

Among the bulbous plants Lewis collected was western spring beauty (Claytonia lanceolata). Growing from a corm, it produces succulent leaves and three- to eight-inch stems of dark pink flowers in early spring. It is easily naturalized in a woodland or shade garden. (Zones 4-8, 8-3.)

Camas (Camassia quamash) grows from a bulb that was a major food source for Native Americans. It grows 12 to 18 inches tall, producing straplike leaves and spikes of violet-blue, star-shaped flowers in spring. It grows best in a moist site-especially in spring-and full sun or part shade. (Zones 4-10, 12-1.)

Herbaceous plants collected on the expedition included Lewis's perennial flax (Linum lewisii, also listed as L. perenne var. lewisii), which is native to dry prairies and mountainsides. It thrives in sites with dry, well-drained soil and full sun and is a good choice for rock gardens and dry meadows. It bears delicate blue flowers along its wispy 12- to 24-inch stems for several weeks in early summer. (Zones 7-9, 9-7.)

The white tufted evening primrose (Oenothera caespitosa) grows best in dry soil and full sun, and it tolerates considerable drought. The deeply toothed leaves are covered with silvery hairs, and white to pink flowers open at night throughout summer. It is a fine choice for xeriphytic borders. (Zones 4-8, 8-1.)

A hardy annual native to prairies and open woodlands, Rocky Mountain bee plant (Cleome serrulata) thrives in dry, sandy soil in full sun or part shade. Stems rise two to five feet, producing attractive compound leaves and showy clusters of pink, lavender, or white blooms. Rocky Mountain bee plant adds color to flower borders and sunny meadows all summer.

Namesakes

Lewis and Clark's achievements are celebrated in the species names-specific epithets-of several plants, including Lewis's perennial flax. But the ultimate tribute came from botanist Frederick Pursh, who in his Flora Americae Septentrionalis (see sidebar, facing page) commemorated the explorers in the genus names of two plants new to science.

Bitterroot (Lewisia rediviva), a fleshy-rooted perennial from the mountains of the West, attracted lots of attention in M'Mahon's seed store, where he exhibited it after coaxing new growth from its shriveled, dry roots. Indians ate the ropy roots fresh or dried, but Lewis found them "bitter and naucious to the pallatte [sic]." Bitterroot is widely distributed throughout the West, where it thrives in dry climates with a long, cool growing season. It develops a rosette of leaves in late summer that persist throughout winter. Showy two-inch, rosy pink flowers appear in early spring, after which the plant goes dormant. Its low-growing habit and preference for dry conditions make it a popular rock garden choice. It is particularly abundant in Montana, where it was designated the state flower in 1895. (Zones 4-7, 8-3.)

Clarkia (Clarkia pulchella), also called ragged robin, was known only as an herbarium specimen until seeds were collected by Douglas. Native from the Rocky Mountains to the Pacific Northwest, this annual prefers a sandy, well-drained soil and a sunny site, and does not tolerate heat and high humidity. In warm climates, it needs some afternoon shade. Its delicate pink, rose, purple, red, or white blooms are held on two- to three-foot stems, making it a good choice for borders and cut flowers.

Today, many of the plants originally collected or described by Lewis and Clark have been woven into our landscapes, tamed by cultivation. But it's tempting to think about how they looked through the eyes of those explorers-growing wild on the windswept prairie, creeping among rocks of the Bitterroot Mountains, hugging the steep banks of the wild Missouri or Columbia Rivers. As the 200th anniversary of their journey approaches, perhaps the most fitting tribute to Lewis and Clark would be to add a few more of their discoveries to our gardens. m

Rita Pelczar is Associate Editor of The American Gardener.

Resources

• Flora Americae Septentrionalis (Flora of North America) by Frederick Pursh. Originally published in 1813. Reprinted in 1979 by Strauss and Cramer, Braunschweig, Germany.

• Herbarium of the Lewis and Clark Expedition, Volume 12 of The Journals of Lewis and Clark edited by Gary E. Moulton. University of Nebraska Press, Lincoln, 1999.

• The Lewis and Clark Collections of Vascular Plants: Names, Types, and Comments by James L. Reveal, Gary E. Moulton, Alfred E. Schuyler. Academy of Natural Sciences of Philadelphia, Pennsylvania, 1999.

• Lewis and Clark Trail Heritage Foundation, Inc. www.lewisandclark.org.

Sources

• Forestfarm, Williams, OR. (541) 846-7269. www.forestfarm.com. Catalog $4.

• Ceanothus sanguineus, Ribes aureum, Symphoricarpos albus.

• Las Pilitas Nursery, Santa Margarita, CA. (805) 438-5992. www.laspilitas.com. Catalog costs vary. Amelanchier alnifolia, Arctostaphylos uva-ursi, Camassia quamash, Linum lewisii, Mahonia aquifolium.

• Siskiyou Rare Plant Nursery, Medford, OR. (541) 772-6846. www.wave.net/upg/srpn. Catalog $3. Lewisia rediviva.