Annuals Botany Garden History Perennials

Geranium or… Geranium?

By Julie Boudreau

Everyone loves anecdotes, even gardeners! There are two very popular plants called geranium. Two plants very different in their appearance and their mode of growth, which, despite their very distinct appearance, are called geranium. How did this happen? Here is the story:

Geranium image: Steve Bidmead on Pixabay; Pelargonium image: Catceeq on Pixabay. Editing: Julie Boudreau in Canva

Discovering the First Geranium

Being widely present in Europe and particularly in the Mediterranean region, the true geranium has been known to botanists since the dawn of time. It is almost impossible to trace the first time the word “geranium” was used to refer to this plant. But it is a name that has traveled and spread. This is how Linnaeus made it official in his famous book Species plantarum in 1753.

Linnaeus is a botanist of Swedish origin (1707-1778) of great importance. We can say that it was he who decided that all living organisms on Earth would have a Latin name, consisting of two words. A genus and a species. Because before Linnaeus, there was a bit of confusion!

We can say that it’s a bit Linnaeus’s fault if we still experience a certain confusion today when we talk about geraniums! Image: Wikimedia Commons

So, Linnaeus looks at this plant, which is already called Geranium and he confirms: from now on, this plant will have the Latin name Geranium!

So far, so good! With the discovery of America and explorations in Africa and Asia, we will realize that the Geranium genus is widespread almost everywhere in the world! More than 350 species!

This true geranium is what is commonly called the perennial geranium. We say this about it to distinguish it from the other, the annual one. However, here too, a little confusion sets in. In truth, in the true Geranium genus there are perennial plants, but also biennials and annuals.

Cranesbill geranium (Geranium sanguineum) is a “real” geranium! Image: Didier Descouens on Wikimedia Commons

The Second Geranium Arrives

The second geranium was discovered almost by chance, by Paul Hermann. Hermann is a doctor and botanist of German origin, who will be director of the chair of botany in Leiden, the Netherlands. After his studies, he was appointed medical officer of a ship en route to Sri Lanka. The year is 1672, approximately. The journey to this island in the south of Africa is perilous. The whole crew is sick and they decide to make a stop in South Africa, just to regain strength.

Paul Hermann is also known for his superb illustrations. What he thinks is a Geranium on this board is actually a Pelargonium! Image: Wikimedia Commons

It was there, at the foot of Table Mountain, that he discovered a two-meter-high plant, covered in flowers. He will have specimens of several plants sent to Leiden, including this new plant. Most of these discoveries will not reach their destination, but the geranium will! And it will quickly become a popular plant.

Table Mountain, South Africa. It was at the foot of this rocky plateau that Paul Hermann discovered the first Pelargonium. Image: Hilton Teper on Wikimedia Commons
Funnel-leaved pelargonium (Pelargonium cucullatum) was first collected by Paul Hermann in South Africa. It has long been called Geranium cucullatum. Image: Didier Descouens on Wikimedia Commons

Without thinking too much, we give the plant the name Geranium. And life goes on!

This famous geranium, which we call the annual geranium, also reserves its share of surprises. In truth, in its native Africa, the plant is perennial and large specimens even have a woody base. It is only in areas where frost exists that it dies in winter, due to the cold.

This “annual” geranium also has more than 250 species, mainly distributed in the eastern part of the African continent. It is also the place of origin of the plant which explains its great tolerance to heat and drought.

A Confusion That Could Have Been Avoided…

If only we had listened to Dillenius! In 1732, this German botanist living in England published a work, Hortus Elthamensis , in which he suggests that we should separate geraniums and geraniums! He even proposed the name Pelargonium to name the plants discovered by Paul Hermann 60 years earlier.

Dillenius knew there was something fishy going on. Image: Wikimedia Commons

He highlights the big differences between the two plants. Notably the fact that the flower petals of “real” geraniums all have the same shape. In the “other” geranium, there are three large petals and two smaller petals.

In Hortus Elthamensis, Dillenius proposes to separate the genres, but Linnaeus will do as he pleases! Image: Wikimedia Commons

We know that Linnaeus and Dillenius knew each other well, because Linnaeus visited our keen observer around 1736. It is not impossible that they had discussions about geraniums over a good cup of tea!

Despite everything, in 1753, the great Linnaeus, supreme master of binomial nomenclature (a two-word Latin name) named these “other” geraniums… yes, Geranium!

And it is thus, because of Linnaeus, that two plants, although so distinct, will bear the name Geranium. This will last almost 40 years!

In 1753, Linnaeus persisted and signed. They are all geraniums! The Geranium triste is actually a Pelargonium triste , exclusively native to South Africa. Image: From Species Plantarum

One Man Saves the Day… 40 Years Later

It was the French botanist Charles Louis de l’Héritier de Brutelle (that’s his full name!) (1746-1800) who had the audacity to put the whole debate surrounding geraniums back on the table.

In 1789, he officially separated the two genera and imposed the name Pelargonium for Paul’s beautiful geraniums. In doing so, he also pays a little homage to Dillenius who had already noticed the error.

From this story, I always find it interesting that we waited almost 10 years after Linnaeus’ death (1778) to make the modification. As if we didn’t dare contradict the great Swedish botanist!

Even today, this imbroglio has left its traces, because in North America we still speak of geraniums to designate “perennial” geraniums, called Geranium in Latin, and “annual” geraniums, called Pelargonium .

Julie Boudreau is a horticulturist who trained at the Institut de technologie agroalimentaire in Saint-Hyacinthe, Québec. She’s been working with plants for more than 25 years. She has published many gardening books and hosted various radio and television shows. She now teaches horticulture at the Centre de formation horticole of Laval. A great gardening enthusiast, she’s devoted to promoting gardening, garden design, botany and ecology in every form. Born a fan of organic gardening, she’s curious and cultivates a passion for all that can be eaten. Julie Boudreau is “epicurious” and also fascinated by Latin names.

3 comments on “Geranium or… Geranium?

  1. Geraniums are only now becoming popular here, so are only now becoming confusing, at least for the Pelargoniums that are not ivy geranium or ‘Martha Washington’ geranium. I still know them as geraniums, but the name of zonal geranium is making a resurgence.

  2. A great story, thank you! Growing up in Australia, the only “Geranium” I knew was the Pelargonium, and when I moved to Canada, I was introduced to a different plant also called a Geranium. It was confusing, and encouraged me to investigate the differences between them. I didn’t know that Linnaeus had had a role in creating this (and my) confusion! Thanks for elucidating this fun bit of botanical history.

  3. Joel LeGrand

    I was corrected on a blog, for posting that tomatoes are annuals, because they are not cold hardy in zone 1-8.
    I was told that a perennial is a plant that grow for three growing cycle or more. A cycle is four seasons or a year.
    Therefore a fig tree is a perennial even if it freezes in an Antarctic ice storm. I guess that makes sense,
    but who would plant a fig tree in Antarctic ice storm.
    Tis is an enlighten article & why I have fan for so long, Thank you.

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