Lewis's Specimen of Bitterroot

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Figure 7

Lewis's Specimen

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tinted drawing of lewisia rediviva


The "T.M." in parentheses stands for Thomas Meehan (1826-1901), a botanist at the Academy of Natural Sciences who, in the late 1890s, found many of Lewis's specimens at the American Philosophical Society, where they had lain untouched and forgotten for three-quarters of a century. He moved them to the Academy's collection, mounted them, and in 1898 published the first list of the Lewis and Clark Herbarium. He attests by his initials that it is he who has labeled these few remains of Lewis's specimen—parts of a flower or two—which Frederick Traugott Pursh (1774—1820) had named Lewisia rediviva in 1814. Pursh was the young German botanist and former curator for the Philadelphia naturalist Benjamin Smith Barton. In 1807 Lewis entrusted his entire collection to Pursh for organization, classification, and entry into the corpus of contemporary botanical literature.1

The phrase "Near Clark's R. Jul. 1st 1806 Lewis," written by Frederick Pursh, relates that Lewis collected the specimen on July 1, 1806 in the vicinity of Travelers' Rest near the river that Lewis had named for his "worthy friend and fellow traveller Capt. Clark," but is now called the Bitterroot River. Journal editor Gary Moulton believes that Lewis's journal entry for July second suggests that he might have collected it on that day instead: "I found several other uncommon plants specemines of which I preserved." But that distinction is of no significance here.

The next sentence, also in Pursh's handwriting, states first that the calyx, or group of sepals, consists of six or seven leaves. In the photograph the sepals are the pale leaves behind the pink petals. The corolla consists of "many pedals" (petals) and many "Tamina" (stamens). The stamens in the center, surrounded by the pink petals, are the male organs of the flower; they are topped by what Pursh called capsula, but now are called anthers. Meehan may have added Pursh's name to this label. The white envelope at upper right is the "packet" that would have held the petals and other elements that had dropped off the flower.

But where are the key elements of the specimen? Why is there no root, stem, sepal or leaf accompanying the bedraggled petals? Those elements are basic to the identity of the species. Pursh answered that question in his comment on the plant in his book, Flora Americae Septentrionalis (1814):

This elegant plant would be a very desirable addition to the ornamental perennials, since, if once introduced, it would be easily kept and propagated, as the following circumstance will clearly prove. The specimen with roots taken out of the Herbarium of M. Lewis, Esq. was planted by Mr. M'Mahon of Philadelphia, and vegetated for more than one year: but some accident happening to it, I had not the pleasure of seeing it in flower.2

Pursh's reference was to the Irish-American horticulturist and seed merchant Bernard McMahon (1775-1816), who emigrated to America in 1796.3 In 1806 Thomas Jefferson named him as one of two nurserymen to grow the seeds and roots brought back by Lewis and Clark; the other was William Hamilton (1745-1813), a wealthy Philadelphian and a dedicated botanist and plant collector. It is thought that the "accident" Pursh referred to may have been the well-meaning McMahon's excess of care and attention, which led him to over-water the dormant root, unaware that it belonged to a dry land species which still held enough moisture to enable its rejuvenation.

On the other hand, it could have been that McMahon only thought it had died. Apparently neither Lewis nor Clark heard any Indian relate that the bitterroot would suddenly go dormant at the time when most other flowering plants were just getting ramped up for the summer's show, and would remain dormant until the following May, except for its display of a little cluster of leaves sometime before winter's snow began.[ fn] Even today, home gardeners who wish to transplant L. rediviva to their rock gardens need to be advised to mark the spot where this season's plants are last seen with a little pile of pebbles, to avoid accidentally ruining the rootstock with pre-season tillage.[ /fn] Surely Lewis would have made a special point of that fact, if he know of it. But evidently McMahon discarded the remains on the assumption the root was dead, and there appeared to be no hope that the bitterroot's elegance would come to civilized light until some other traveler brought back a viable specimen from the mountain west.

Figure 8

What Lewis Saw


white bitterroot flower

We might wish that either Lewis or Pursh had left us some written record of what they talked about during those days or weeks that comprised the only meeting they ever had. But to them it wasn't history, only the business of the day, and it would be documented in Pursh's professional descriptions of all 134 vascular plants Lewis presented to him, which were to have been included in the third and final volume of the illustrated account of Lewis and Clarks Tour to the Pacific Ocean.4

It would have been a difficult and time-consuming process. They would have devoted most of their time to discussions of the 94 new species that were among the 134 specimens Lewis brought with him. In order to write the formal diagnosis that would be required for the official admittance of each specimen into the corpus of botanical taxonomy, Pursh would have examined each specimen to acquire an initial impression of its identifying characteristics. Then he would have queried Lewis at length in a systematic way in order to organize his own impressions into a narrative in botanical Latin. He would jot down some essential details on the specimen sheet, but would also take copious notes on a separate sheet that would become the diagnosis.

The most challenging specimen was the one that was lacking several key pieces, most notably the root. It was also the most intriguing one, given its importance as a native food, and its capacity to come to life after being out of its habitat for many months. (The rest of its life story—that after it produced its flowers and seeds its parts would dry up and blow away, and what was left would sink into subterranean dormancy before summer's heat descended, and remain hidden through the weeks when most other plants were doing their blooming and seed bearing, then as autumn approached its peak would sent up a few of its delicate, fleshy leaves that would remain green all winter—all of that strange story would await a more general acquaintance.)

This exotic plant had to keep its secrets for another half-century before its beauty could seduce curious  eastern eyes. Meanwhile, the only alternative was Pursh's dispassionate "diagnosis," a 72-word paragraph consisting of terse answers to ten key questions that its author might have discussed in a conversation with Lewis himself. However, it would have been of no use to anyone but another well educated botanist, because it was written in botanical Latin.5 Decades went by while the small envelope containing the pitiful remains of the plant Pursh had named for him languished in the herbarium at the Royal Gardens of Kew, in a suburb of London, where Pursh had left them. In 1830 the manager of the Gardens published an English translation of part of Pursh's diagnosis.

In the United States they were out of sight and out of mind. Pencilled or pen-and-ink drawings are more useful to taxonomists than colored images because they can visually define the parts of a plant in minute detail, such as the veins in a leaf. As to public familiarity with the bitterroot, one of the few signs that colored representations were missed appeared in the American Repertory of Arts, Sciences, and Manufactures in 1841, under the heading "Fruits and Valuable Plants of the Oregon"6 "There is also the Bitterroot, a carrot-shaped root, growing in dry land, not particularly pleasant to the taste, but esteemed wholesome by the Indians and hunters." The story of its apparent annual death and rebirth was still unknown to botanical science.

  • 1.  Pursh was also recommended as the best American botanist to illustrate Lewis's proposed (but never written) volume on the expedition's discoveries in the natural sciences, including botany. For an example of Pursh's talent as an artist see his rendition of <a href="/article/1330">Clarkia pulcella</a>.
  • 2. Flora Americae septentrionalis, 2 vols. (London: White, Cochrane, and Co., 1814), No. 437, 2:368.
  • 3. McMahon's principal achievement as a botanist was his initial authorship of The American Gardener's Calendar: Adapted to the Climates and Seasons of the United States, which was published annually from 1806 until 1857. Allen Lacy, "Bernard M'Mahon's Declaration of Independence," in Farther Afield: A Gardener's Excursions (New York: Macmillan, 1986).
  • 4. For details of Lewis's Prospectus, see Donald Jackson, <i>Letters of the Lewis and Clark Expedition with Related Documents</i> 1783-1854, Second Edition, 2 vols. (Urbana: University of Illinois Press, 1978), 2:394-97. See also <i>The Lewis and Clark Herbarium: Images of the Plants Collected by Meriwether Lewis and William Clark, 1804–1806</i>, presented by the University of Maryland and The Academy of Natural Sicences in Philadelphia in cooperation with Cornell University <http://www.plantsystematics.org/reveal/pbio/LnC/LnCpublic.html> (accessed 18 November 2014).
  • 5. As a botanical term, a diagnosis is a paragraph of aphoristic statements in the ablative case which describe the most distinguishing features of a plant, expressed in a blend of classical Latin with Latinized words from Greek, English and other languages, now collectively known as "botanical Latin." About 80 per cent of all generic names (such as Lewisia) and 30 per cent of all specific epithets (such as rediviva) are from languages other than Latin and Greek. As the worldwide lingua franca of botanical science, its lexicon and grammatical rules are strictly governed and enforced by the ICN, or International Code of Nomenclature for algae, fungi, and plants, founded in 1905 after a long and tortuous search for clarity and simplicity. For example, with the publication of his Systema Naturae in 1735, Carl Linnæus had chosen to limit his diagnoses to a maximum of 12 words in the interest of brevity and convenience, but by 1814—coincidentally the year of publication of Nicholas Biddle's paraphrase of the journals of Lewis and Clark—the science of botany had gained so much momentum that the 80-year-old limitation was a burden on the science, which accounts for Pursh's 72-word descriptive document. In 2011, at the 18th International Botanical Congress, the historic requirement that the validating diagnosis must be in Latin was changed to allow new names to be validated with diagnoses in English. William T. Stearn, Botanical Latin: History, Grammar, Syntax, Terminology and Vocabulary, 4th ed. (Trowbridge, England: David & Charles Publishers, 1993), 3, 6, 143.
  • 6. Until the State of Oregon came into existence in 1848, the region of which it was a part was commonly known as "the Oregon." Similarly, at the time of the Lewis and Clark Expedition the region east of the Upper Mississippi River was informally referred to as "the Illinois," until the Territory of Illinois was officially established in 1809, and the State nine years later. "Illinois" was a French version of an Indian exonym for the remnants of the "illinois Confederation," specifically in reference to the language family shared by the many tribes that comprised it.