Botanical chronicles: Part 1- Genus and species names

The world of botany is a rich tapestry woven with the threads of exploration, discovery, and the fascinating stories of the individuals who dedicated their lives to understanding the plant kingdom. One intriguing aspect of this botanical journey is the association of names with genus and species. Each plant bears a scientific identity that originates with the botanists who have described it.

In this blog post, I’m delving into the way a plant species gets its name and the stories behind the names of authors associated with botanical nomenclature.

Carl Linnaeus (1707-1778): The father of modern taxonomy

No exploration into botanical nomenclature can begin without acknowledging Carl Linnaeus. This Swedish botanist revolutionized the way we classify and name plants. Linnaeus developed the binomial system, assigning a two-part Latin name to each species. The first part represents the genus, while the second signifies the species. Let’s take the example of Paeonia lactiflora, the common garden peony.

Image from: Greene, Edward Lee (1912) Carolus Linnaeus. Philadelphia: Chirstopher Sower.

The complete scientific name of a plant

When we encounter a scientific name like Paeonia lactiflora Pall., it follows this standardized system known as binomial nomenclature. Let’s break down this particular example for the common garden peony and explore why it is written in this way.

**1. Paeonia: The genus**

The initial segment of the scientific label, “Paeonia,” unveils the genus to which the plant belongs—specifically, the garden peony. This genus serves as a broader classification, grouping together related species. For instance, various peony species, such as Paeonia suffruticosa or Paeonia officinalis, find their botanical home under the umbrella of the genus Paeonia.

In some botanical references, only the genus of a plant may be cited, coupled with the abbreviated name of the pioneering botanist who bestowed it with identity. This practice serves as a succinct nod to the authorship of the genus description and is commonly observed in scientific nomenclature. The abbreviation typically comprises the initial or first letters of the botanist’s surname, followed by a period.

Carl Linnaeus, in his groundbreaking work “Species Plantarum” in 1753, originally described the genus, listing Paeonia officinalis. So, when encountering the genus “Paeonia” with the author abbreviation “L.”, it points to Carl Linnaeus as the botanist who formally characterized and named the genus. However, it is more prevalent to encounter the genus accompanied by the epithet name.

The name “Paeonia” finds its roots in Greek mythology, specifically in the character Paeon, a pupil of the god of medicine, Asclepius. Paeon, using a peony root to heal Pluto, avoided the wrath of Asclepius, who envied his student’s curative prowess. In homage to this myth, the peony plant acquired its name, a practice where Linnaeus, echoing early botanists and herbalists, bestowed scientific significance upon a name steeped in ancient botanical literature.

The genus Paeonia is extensive and encompasses a large number of species, varieties and cultivars (cultivated varieties) within the peony family (Paeoniaceae). Let’s examine now the epithet that identifies the species.

2. lactiflora: the species

The epithet, or second component of the name, “lactiflora“, unveils the specific species to which this peony belongs. It is also referred to as the epithet and often imparts insights into the plant’s characteristics, such as flower color or leaf shape, or pays homage to another esteemed botanist.

The specific epithet “lactiflora” is derived from Latin. The word can be broken down into two parts:

“lacti-“: This part of the word comes from the Latin word “lac,” which means milk.

“-flora”: This part is derived from the Latin word “flos,” meaning flower.

So, “lactiflora” translates to “milk-flowered” or “milky-flowered.” This term likely alludes to the milky or creamy appearance of the flowers of the original Paeonia lactiflora specimen, characterized by a simple, whitish bloom—distinct from the elaborate varieties that grace contemporary gardens. This unpretentious blossom laid the groundwork for the lavish and diverse realm of present-day garden peonies, exemplifying the transformative journey these flowers have undertaken over time through selection and hybridization.

Image from: Botanical Magazine, vol. 42 (1815): pl. 1756.

3. Pall: The author’s abbreviation

The “Pall,” at the end of the name is an abbreviation of the author’s name who formally described and named the plant. In this instance, “Pall.” stands for Peter Simon Pallas (1741-1811), a German naturalist and explorer. Pallas described this species in 1776 and published it in a Russian publication. At the time, the description was written in Latin. English is now the accepted language for new species and other taxa. A taxon (plural: taxa) is a unit of classification used in taxonomy, the science of naming, defining, and classifying living organisms.

Because of the authorship of Pallas, a later description of the same species as Paeonia albiflora (see above image from vol. 42 of the Botanical Magazine, 1815) is not scientifically valid and Paeonia lactiflora is the correct name to use today.

It’s important to note that while the genus name is always written with an initial capital letter, the specific epithet is written in lowercase. Whether only the Latin genus is given or when the entire species is written together, they are italicized or underlined in scientific literature (this latter preferably not on the web). However, the abbreviation of the author is not italicized. So, when we say Paeonia lactiflora Pall., we are providing a precise and internationally recognized way of identifying a particular species of peony, emphasizing its genus (Paeonia), species (lactiflora), and crediting the individual who officially classified it (Pall. for Pallas). This standardized naming system ensures clarity and consistency in the identification of plants across the scientific community, regardless of language or geographic location.

It is always provided when describing a species for the first time. It helps to precisely identify and reference the species.

In botanical gardens and when documenting plant specimens, creating herbarium labels, or maintaining botanical records, the complete scientific name, including the author’s abbreviation, is used to accurately catalog and identify plant specimens. In scientific research papers, articles, and botanical publications such as floras or monographs, the full scientific name is also typically used.

Scientific name versus common name

In the horticultural world or plant-lore, however, the author’s abbreviation is rare. In many instances, the common name is used. Common names, also called vernacular names, may refer to more than a plant and bring confusion. A plant may have more than one common name. For example, common garden peony and Chinese peony both refer to Paeonia lactiflora. A joint use of the scientific and common names is preferable.

Finally, there are more than the genus and species combination in nomenclature and classification of plants: above are families, for example; under there could be subspecies and varieties. This should be addressed in future blog posts.

Below, some cultivars of Paeonia lactiflora, all from my garden: