John Lawson Exhibit: How Plants are Named
How Plants Are Named with Some Examples Selected from the John Lawson Plant Collection
Planet Earth supports thousands of different plant species. The same species may have different
names in different languages. The name for our common Dandelion is an anglicized corruption of the French
"dent-de-leon," or lion’s tooth. The German "Lindenbaum" is called "Basswood" in English. The same plant may
be given different common names even within one country. A common American shrub, covered in Autumn with red-seeded
orange pods, is known to most Americans as Strawberry Bush. Folks in the Appalachian Mountains call this same shrub
"Hearts-a-bustin." Finding the correct name for a plant during the colonial period in America was further
complicated by the fact that immigrants often applied European names to American plants that resembled familiar
plants from home, but which were really different species.1 A common English tree is
called a "Sycamore." It belongs to the maple family. When English colonists arrived in America they began calling
a tree with similar leaves, "Sycamore." It turns out that the American sycamore belongs to an entirely different
family. Many colonists simply used the local Native-American names. Examples of Native-American names include
Yaupon, Chinquapin, Pawpaw, Ipomoea, Titi, Puccoon, and Sassafras. Still other plants indicate Native-American
associations. These names include Indian Cucumber Root and Squaw Huckleberry. All of the above-named plants are
represented among the Lawson Plants.
Plants have always been of economic importance to humans. Plants provide food and medicine. We make our homes
and clothing from them while poets, artists, and gardeners receive inspiration from their beauty. Even in
prehistory it was necessary to name plants correctly. Mistaking a poisonous plant for an edible one could have
fatal results. Over two thousand years ago, Greek physicians began to produce plant identification books, called
herbals. The books contained illustrations and brief descriptions of useful plants. I have found modern equivalents
of these ancient books for sale at herb markets in Costa Rica. The problem of differing common names among the
several languages was addressed during medieval times by writing plant herbals in the scholarly language of
Latin.2 While it may be reasonable to expect a physician or naturalist to memorize a
few hundred descriptions of useful plants, the task became unmanageable during the Age of Exploration when
collectors, like John Lawson, began sending thousands of specimens back to Europe from all parts of the World.
Nearly half a century after John Lawson’s death, Carl Linnaeus developed a system that greatly facilitated the
process for classifying plants. Consider the information given in the footnote below.3
The Latin words and numbers refer to published descriptions of plants that resemble the mounted specimen.
The first entry compares this plant to Candy Cassidony as appears in a book by John Ray. John Ray made the first
attempt to describe all known plants. He published Historia Plantarum in three volumes between 1686 and
1704. There is evidence that James Petiver gave John Lawson a copy of Ray’s book when Lawson was in England in
1708. The last entry in this footnote is in a classical pre-Linnaean format. It reads Staechas citrina globosa
et amplo flore Cretica. A loose translation might read: "This plant is illustrated in plate 987 and is described
on page 814 of a book by Burrelier that describes the flora of Crete. The plant bears abundant rounded heads of
pale yellow flowers." This string of Latin is known as a Latin polynomial. Linnaeus’ innovation was to reduce all
of this information to an abbreviated form. Linnaeus created a "scientific name" consisting of the first two words
in the Latin description , Staechas citrina, together with the author of the description of that plant. This
combination is called a Latin binomial. Linnaeus assumed that all serious naturalists would have access to the
existing botanical literature and that they could use the "short description" to look up the detailed original.
Thus, if two authors gave different names to the same plant the interested reader could compare Candy
cassidony Ray with Staechas citrina Bourrelier or Elychrysum criticum CB. All three of these
scientific names are correct Linnaean binomials. The book's authors are given as a helpful reference. Author
names are referred to as the authority. An authority is the person who first published a Latin description of the
species. A complete scientific name must consist of the Latin binomial and the authority. Candy cassidony is a
binomial while Candy cassidony Ray is a scientific name. The word Candy is the generic name while the term
cassidony is the specific epithet. This naming practice cites the more general category first followed by the more
specific. For instance my surname is Bellis and my given name is Vincent. I am Vincent of the Bellis clan. In
botanical Latin my ‘binomial’ would be Bellis vincent. Botanists say the Bellis represents the generic, or
genus, name. Vincent is the specific, or specific epithet.
Why the italics and why is the generic name capitalized while the specific epithet is in lower case? Remember that
the scientific name is a condensed version of a longer Latin description. By convention we begin our sentences with
a capital letter. Since the generic name was usually derived from the first word in the Latin description it was
capitalized. The specific epithet was derived from the second word (in the descriptive sentence) and is not
capitalized. Most learned works during this period were printed in an Italic font. The authority was printed in
Roman font to more clearly distinguish it from the binomial. Remember that the ‘name at the end’ is a reference to
an author or authority and is not part of the description of the plant.
This scientific and systematic approach to naming plants greatly helped reduce confusion. Botanists could now
compare similar specimens and descriptions from various locations. Plants belonging to the same species but
bearing different binomials could be combined under one name. Here is one example. The weed that we know as
Dandelion was identified in several European languages by terms that described the individual tooth-like flowers
(Leontodon = Lion’s tooth) of the plant. Linneaus gave this plant the binomial Leontadon taraxacum. Since
Linnaeus was the authority the scientific name became Leontadon taraxacum L. The ‘L.’ refers to Linnaeus.
A later specialist moved this plant to a new genus that he called Taraxacum. This authority was Frederich Heinrich
Wiggers, 1746-1811. The accepted modern scientific name for the common dandelion is Taraxicum officinale.
Wiggers. The specific name, officinale, refers to the wide use of this plant in herbal medicine.
"Officinale" means "of the shops or herb markets."
When a major change occurs two authorities may appear in the scientific name. Botanists often examine old
collections of dried plants, or herbaria, in order to gain a specialists understanding of a particular group.
We see evidence of this on page 145-47 of the Lawson plants.4 Information on this label
shows that James L. Reveal of the University of Maryland examined this specimen sometime in 1989. He identified
it as Polypodium polypodioides (L.) Watt. var michauxianum Weatherby. The information on this label
indicates that this plant was first described by Linnaeus. He assigned it to a different genus. Later David Allen
Poe Watt (1830-1917) transferred it to the genus Polypodium. Still later Charles Alfred Weatherby (1875-1949)
recognized more than one variety of this species and designated this one as michauxianum. Andre Michaux
was a French botanist who collected plants in eastern North America in the years just after the American
Revolution. Michaux collected widely in western North Carolina. The French had helped push the English out of
the United States and were interested in discovering new plants having potential commercial value.
The Linnaean System of Plant Classification was published in 1753 as Species Plantarum. This system remains
the basis of modern plant classification and nomenclature. Over the years botanists have developed rules to govern
the assignment of scientific names. One basic rule is that to be accepted as a valid name the description of a new
species must be published in Latin in a recognized botanical publication. The rules governing plant names are
published as The
International Code of Botanical Nomenclature. Botanists periodically organize International Botanical Congresses
in order to review the Code and to resolve disputes. The Royal Botanic Garden at Kew in London, England attempts
to record all plant descriptions as they appear in the literature. The Index Kewensis lists all known specific
epithets alphabetically under each genus.
1 Note attached to a plant on page 242-129b in Lawson’s hand. "Feb. 18th, 1711. Evergreen. I formerly
took this to be a sort of privett but am of the opinion it is ye gallberry, both bearing a black berry..." NOTE:
This specimen has been identified as Large or Sweet Gallberry.
2 Note attached to a plant on page 171-65 in printed Latin. "12. Candy Cassidony. Ray 282.8
Elychrysum Creticum CB.264.6. Chrysocome 5 qua Cretica Clus.327. Chrysocome sive Staechas
citrina Cretica Park,69.8. Staechas citrina globoso & amplo flore Cretica Burrelier pl. 987.lc opt. 814.
[This last author has given a very accurate Figure of this plant, which is so beautiful an ornament in our most
curious Gardens.] NOTE: This plant has been identified as Rabbit Tobacco or Cudweed.
4 Note the annotation label at the bottom of p.145-47. This is an annotation label affixed to the
herbarium specimen by an American fern specialist who was visiting the British Museum to examine the Lawson
plants. NOTE: This plant has been identified as Resurrection Fern.