Monstera deliciosa is among the most widespread houseplants of all time. Its huge, dramatically split leaves make for eye-catching decor, and its easygoing shade-tolerant nature is popular with beginners and experts alike. And that’s not even including its white-splashed variegated forms, which are under staggering demand around the world.
Like any popular conversation topic in the age of the internet, Monstera deliciosa has also attracted its share of controversy and misinformation. In this article I’ll address one particular discussion that pops up regularly: the identity of Monstera borsigiana.
The “borsigiana” story
If you join any houseplant groups or communities online, you’ll probably start to hear another name mentioned in relation to Monstera deliciosa plants – “borsigiana”. Depending on the source, it’s either described as a species of its own (Monstera borsigiana) or a variety (M. deliciosa var. borsigiana).
Various characteristics are used to distinguish “borsigiana” from “true” M. deliciosa. Most often, “borsigiana” is said to have smaller leaves and a thinner stem with longer spaces between leaves. Sometimes the shape of the leaf stalk (petiole) is highlighted – with “borsigiana” having smooth edges, and “true” M. deliciosa having ruffles at the point where it meets the leaf.
Some people point out seemingly mislabelled plants, which have been sold as M. deliciosa but are actually “borsigiana” and therefore misleading scams. Other people are excited to know that there is another subspecies of their favourite plant to add to their collection.
|Monstera borsigiana is a distinct species or subspecies||Monstera borsigiana is an outdated botanical synonym for Monstera deliciosa|
The best source for accurate and up-to-date botanical names is The Royal Botanic Gardens, Kew – a world-leading authority in botany. They host an online database of all currently accepted species and names. And according to that database, Monstera borsigiana is a synonym of Monstera deliciosa.
A synonym is a very precise concept in botany. When someone researches what they believe to be a new species, they create a new name for it. If future research finds that the plant they studied is actually identical to another previously-recognised plant, the name is classed as a synonym. It means the two species are defined as identical, and only one name (usually whichever was created first) is considered correct.
There’s more detail about the history of these particular names in a recent research paper – Cedeño Fonseca, Marco & Díaz Jiménez, Pedro & Zuluaga, Alejandro & Blanco, Mario. (2020). A comparison of Monstera deliciosa and M. tacanaensis, with comments on Monstera section Tornelia (Araceae). M. borsigiana was first named in 1862. It was then downgraded to a variety, M. deliciosa var. borsigiana in 1908. From 1951 onwards, it has been considered purely a synonym for M. deliciosa, and not a distinct species or variety at all.
The name Monstera borsigiana today is effectively like an old-fashioned spelling of Monstera deliciosa. It means exactly the same thing, it’s just obsolete and needlessly confusing. Scientists have classed M. borsigiana as a synonym for M. deliciosa for seventy years, and there is no reason to carry on using such an outdated name.
But these plants look different!
People use lots of different traits to distinguish “borsigiana” from “true” M. deliciosa.
- Stem thickness
- Leaf size
- Amount and type of fenestration (splits and holes) in the leaves
- Presence or absence of ruffles on the edge of the petiole (leaf stalk)
- Length of stem between leaves
- Overall shape of the leaf outline
All of these variations can ultimately be explained by the fact that M. deliciosa as a species has a huge amount of natural diversity. That diversity is expressed in two ways: within the lifetime of an individual plant, and between different individual plants.
One of the most significant factors is the maturity level of the individual plant. A juvenile M. deliciosa plant is a thin vine with small, unsplit, heart-shaped leaves that crawls along the forest floor. When it finds a tree trunk, it begins to climb it by gripping the bark with aerial roots. It then starts to develop a mature form with a thicker stem, much larger leaves, fenestrations (splits and holes in the leaves), and eventually flowers and fruit.
In plants, ‘maturity’ isn’t simply a matter of age – it’s also controlled by environmental factors. When a vine is cut to propagate, the new growth will revert to a more juvenile state than the parent plant. If a climbing plant has no support to climb, it can live indefinitely in its juvenile state without maturing. Ideal tropical conditions like bright light, high temperatures, and plenty of space can prompt a plant to mature much more quickly than a suboptimal environment – people who have been told that they have a “borsigiana” might be surprised when it magically grows into a “true” M. deliciosa in good conditions!
There is a lot of variation throughout the species – so much that even botanists previously believed it was multiple different species. In some plant species, every individual naturally looks very similar to the next. M. deliciosa is not one of them!
Populations that originate from different places in the wild can have their own unique traits, and even closely related individuals can vary widely. Many cultivated M. deliciosa plants are grown from seed, which means there is potential for a lot of genetic diversity even between plants from the same source.
Although it’s pretty easy to confirm that Monstera borsigiana is a synonym for M. deliciosa if you know where to look, the myth still persists. All of the potential variation in the species means that people are often surprised by how different one plant can look from another. Throw in the plausible-sounding name and description of another species or subspecies, and it’s easy to be convinced that M. deliciosa is actually made up of precisely two distinct identifiable forms.
But, although one plant can look very different from another, that doesn’t mean that the entire species divides neatly into two groups. Every trait can vary independently and with no particular relation to others. There’s no way to predict whether a plant will develop, say, ruffled petioles based on how many splits its leaves have. And in fact, perpetuating this idea just leads to even more confusion and disappointment when the two supposedly distinct forms don’t turn out to be consistent or predictable after all. Let’s end the myth for good!