Berberis aquifolium Pursh

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Lewis's specimen of Berberis aquifolium

Lewis's Specimen
Used by permission of the Academy of Natural Sciences, Philadelphia.

Botanists periodically review specimens such as Lewis's in order to verify the work of their predecessors, or else to make corrections in the light of more recent discoveries. The notations on the above specimen sheet trace the record of scientific understanding of Berberis aquifolium during the past 200 years.

The notation at extreme upper left of the image above was written by Frederick Pursh, the German (Saxon) botanist who had come to the United States in 1799, and who was given Lewis's entire collection of herbarium specimens for study and classification. It reads: "Lewisia ilicifolia. Great rapids of Columbia with soil among rocks. Apart. 11, 1806."

Pursh first thought the plant represented a new genus, which he considered naming Lewisia in honor of Meriwether Lewis. After further study, however, he decided it properly belonged to an existing genus, Berberis, and that is the one he used in his book, Flora Americae Septentrionalis (Plants of North America), published in 1813.

Ilicifolia (ee-li-ki-FO-lee-uh) is a Latin noun denoting evergreen trees and shrubs; the root of the word is ilex, which is Latin for holly.

The memorandum in the upper right hand corner, also in Pursh's handwriting, reads: "Lewisia ilicifolia Nov: genus [new genus]. Mountain Holly. The flowering stem Springs up from near the ground & is upright; the infertile Shoots trail along the ground. Rich soil among rocks. Great rapids of Columbia. April 11th 1806."

Lewis concluded his detailed description of the plant on February 12, 1806, with the observation that it "resembles the plan common to many parts of the U' States called the mountain holley."

The note "copy Lewis," faintly visible below the date, may have been entered by Thomas Meehan, the botanist at the Academy of Natural Sciences who found the long-neglected Lewis and Clark herbarium at the American Philosophical Society in 1896.

Beneath this label is written "Pursh's specimen." The rubber-stamped words are: "Ex. [from] Herb[arium of] A. B. Lambert."

Pursh took most of Lewis's specimens to London in 1811, and worked on them there under the patronage of A. B. Lambert, a wealthy cabinet--that is, laboratory--botanist. The collection remained in Lambert's custody from the time of Pursh's death in 1820 until his own death in 1842, after which part of it was purchased at auction by a wealthy young American botanist, Edward Tuckerman. Fourteen years later, Tuckerman gave the Lewis and Clark specimens to the Academy of Natural Sciences.

The handwriting at left, just below Pursh's note, reads: "Torrey & Gray in Flora N. Amer 1:51 footnote say the separate leaflets are from a Menzies collection in the Banks herbarium." It is signed "J. A. Mears 3/ [19]76." Mears was a curator at the ANS.

The reference is to Flora of North America, by John Torrey and Asa Gray (2 vols., New York: 1838-40). James Mears was a botanist at the Academy in the 1970s.

Sir Joseph Banks obtained many specimens gathered by naturalists around the world which he added to his own extensive collections that he had obtained mainly in Newfoundland and Australia. The Banks herbarium is now part of the general herbarium of The Natural History Museum in London.

The typewritten label at lower left reads: "Academy of Natural Sciences/Berberis aquifolium (Pursh)/Det[ermined by]: Erica Armstrong/Date:18 May 1994."

Aquifolium, or "water leaf," suggests the shiny, wet-looking surface of the plant's leaves. Botanist Erica Armstrong recently worked at the Academy.

The printed label at center top reads: "Lewis and Clark Herbarium/Ph.L.C.38: Berberis aquifolium Pursh, Fl. Amer. Sept.: 219. pl[ate].4. Dec (sero) 1813. –Lectotype!–minus leaves from the Menzies sheet. James L. Reveal (MARY [University of Maryland]), Alfred E. Schuyler (PH [Academy of Natural Sciences]) Jun 1998."

Exclusive of the three pale leaves in the center, which came from a collection made by Archibald Menzies (see below), the three specimens Pursh studied constitute a "lectotype." The "type" method of plant classification was designed to stabilize the ranking of species by scientists. Accordingly, the first botanist to describe and name a plant establishes his specimen as the original type material, or "holotype."

But the type method was not introduced until after Pursh's death, so a later botanist has designated Pursh's (Lewis's) specimen as a substitute for the undesignated holotype of Berberis aquifolium.

In 1790, Archibald Menzies, a Scottish physician and naturalist, was appointed by the British government to accompany Captain George Vancouver on a global tour in the good ship Discovery. His primary responsibility was as the ship's surgeon. His natural history responsibilities included making observations on plants, recording their scientific as well as Indian names, and noting whether English settlers might be able to thrive in each place as farmers.

Alfred E. Schuyler is curator of the Lewis and Clark Herbarium at the ANS.

For many years this plant was known as Mahonia aquifolium (Pursh) Nutt. "Nutt." stands for Thomas Nuttall (1786-1859), an English naturalist who came to the U.S. in 1808 and studied botany under Benjamin Smith Barton, one of Lewis's mentors. Nuttall renamed the genus Mahonia in honor of Bernard McMahon (c. 1775-1816), the prominent horticulturist in whose Philadelphia home Pursh began the study of Lewis's specimens.
The accepted name today is Berberis aquifolium.


The Collection

Gary E. Moulton, editor, The Journals of the Lewis & Clark Expedition (12 vols., Lincoln: University of Nebraska Press, 1983–99), vol. 12, Herbarium of the Academy of Natural Sciences, 108 and plate 109.

James L. Reveal, Gary E. Moulton, and Alfred E. Schuyler, "The Lewis and Clark Collections of Vascular Plants: Names, Types, and Comments." In Proceedings of The Academy of Natural Sciences of Philadelphia (1999) 139:1–64.


This page has been reviewed by Richard M. McCourt, Associate Curator of Botany, Academy of Natural Sciences, and James L. Reveal, formerly of the Norton-Brown Herbarium, University of Maryland.