Monstera Obliqua — How to Tell It From Adansonii
The four marks people use, what each one is worth as evidence, and the parts of this question nobody can settle from a photograph — including us.
Most pages about Monstera obliqua open by telling you that you don’t have one. We’re not going to do that, because we can’t see your plant and it isn’t a claim anyone can make from a distance. What we can do is set out what actually distinguishes the two species, be straight about how good the evidence is behind each point, and let you look at your own plant and decide.
One thing is firmly established, and it is about the name rather than about anybody’s plant: the label obliqua is frequently attached to plants that are something else. That makes a label weak evidence in either direction — which is exactly why the marks below are worth working through.
The four marks, strongest evidence first: 1. Stolons — long leafless runners that root where they land. Obliqua is described as producing them; adansonii is not, and this is the one you can observe over a season rather than judge from a photo. 2. Leaf substance — obliqua near-translucent, adansonii noticeably more solid. 3. Proportion of blade missing — far more on obliqua. 4. Margin — obliqua often slightly wavy, adansonii usually straight.
The One Thing That Is Settled
Kew’s Plants of the World Online — the standard reference for accepted plant names — records that the name Monstera obliqua is often misapplied to specimens of the more widespread Monstera adansonii. That is a statement from the taxonomic literature, not from a plant blog, and it is the firmest thing on this page.
Read carefully what that does and does not say. It says the name gets misapplied — so a plant tag reading “Monstera obliqua” is not evidence that the plant is one. It says nothing whatsoever about any particular plant, including yours. A tag being unreliable is not the same as a tag being wrong.
The Four Marks, and What Each Is Worth
These are the characters that specialist growers and nurseries use. They agree with each other, which counts for something. What we have not been able to point to is a published identification key that separates the two species on these characters point by point — so treat the column on the right as seriously as the two on the left.
| Mark | M. obliqua is described as | M. adansonii is described as | How good is the evidence? |
|---|---|---|---|
| Stolons | Readily produces long, leafless runners that travel and root at the nodes | Does not produce them | The most useful of the four. Consistently reported, and it is binary rather than a matter of degree — a runner is either there or it isn’t. It is also the only one you can check on your own plant over a season instead of eyeballing a photo. |
| Leaf substance | Thin to the point of near-translucency; described as paper- or tissue-thin | Noticeably more solid, with some texture to it | Consistent across grower sources, and easy to feel with the plant in your hands. It is a description rather than a measurement, and “thin” is relative to what you have handled before. |
| Proportion of blade missing | Very high — sources describing the sought-after form cite up to around 90% of the blade perforated | Modest; the leaf is mostly intact, with enclosed holes | Widely repeated, but the 90% figure attaches to one form of obliqua rather than to the species — see the section below. Striking when present; its absence proves less than it looks. |
| Leaf margin | Often slightly wavy | Usually straight | The weakest of the four. Consistently stated, but subtle, affected by how the leaf grew, and close to unusable from a photograph. Worth noting, not worth deciding on. |
Use them together, not one at a time. A young adansonii in poor light can produce thin leaves; a photograph can make any margin look wavy. Several marks pointing the same way is worth far more than one, and the one worth waiting for is a stolon.
The Names Are Tangled Well Beyond Adansonii
Two further collisions are worth knowing, because both routinely appear on the same shelves and neither is resolvable from a listing.
“Monstera Peru” is usually a different species entirely. A plant sold under that name is generally Monstera karstenianum: thick, glossy, deeply puckered leaves with no large holes at all. Nobody would confuse the two plants if the labels were different. Separately, collectors use “obliqua, Peru form” for the near-lace plant they mean by obliqua. Same word, two unrelated meanings, both in circulation.
Not all obliqua looks like the famous photographs. The species covers a wide geographic range and a number of forms, and the plant collectors picture — more hole than leaf — is one of them. Others are considerably less dramatic. So the “90% perforated” description identifies the form people want; it does not define the species, and a less lacy plant is not thereby ruled out.
If you want to go to the source, the modern treatment of the genus rests on Madison, M. (1977) “A revision of Monstera (Araceae)”, Contributions from the Gray Herbarium 207: 3–100, which revised Monstera and is where the species boundaries in current use come from.
If Yours Is an Obliqua: What It Needs
This is not a normal houseplant, and treating it as one is the usual reason it dies. A leaf that is close to translucent has almost no water in it to lose and no reserve to buffer a dry afternoon — so this species is intolerant of dry air in a way no other monstera is.
The Canadian problem, stated plainly: a heated home in January is close to the worst environment you could give this plant. Our own winter care page puts a heated Canadian home at roughly 25–30% relative humidity in midwinter. A deliciosa tolerates that and sulks. This plant does not tolerate it.
- Enclosure, not a shelf. People who succeed with it here grow it in a glass case, a converted cabinet or a terrarium, where humidity can be held high independently of the room.
- A very open medium. Sphagnum-based mixes are the norm, for air around fine roots rather than for water retention.
- Bright indirect light, never direct sun. A blade that thin scorches quickly.
- Warmth without draughts — the same 13 °C floor as every monstera, but with far less margin for a cold night against glass.
- Patience. It is slow, and a stressed plant does not bounce back the way an adansonii does.
What We Can’t Tell You
Three things, and we would rather say so than write around them.
- What your plant is. Not from here, and honestly not from a photo either. The marks above are what to look at; the conclusion is yours.
- Whether a particular listing is genuine. We have no way to authenticate a seller. Two questions get you further than any online opinion: where the plant came from, and whether it has produced stolons. A seller who knows their material answers both.
- How firm the four marks are taxonomically. They are consistent among specialist growers, and that is genuinely worth something — but it is not the same as a published key, and we are not going to present it as one. This is the same standard we apply to our climate data: say what is known, name what isn’t, and don’t round the gap away.
One thing worth saying at the end. If you work through the marks and conclude your plant is an adansonii, that is not a disappointment. It is a better houseplant by most measures — faster, more forgiving, propagates from nearly any piece, and it will actually thrive in a room that would kill an obliqua in a Canadian February.
Frequently Asked Questions
How do I tell a Monstera obliqua from a Monstera adansonii?
Four marks are used, and they are worth checking in this order. Stolons: obliqua is described as producing long leafless runners that root where they touch, and adansonii is not — this is the one a grower can watch for over time rather than judge from a photo. Leaf substance: obliqua is described as thin to the point of near-translucency, adansonii as noticeably more solid. Proportion of blade missing: obliqua leaves are described as having far more hole than leaf. Leaf margin: obliqua often slightly wavy, adansonii usually straight. Check your own plant against all four rather than any single one.
Are most plants sold as Monstera obliqua actually adansonii?
The name is very often misapplied — that much is documented rather than folklore. Kew's Plants of the World Online records that the name Monstera obliqua is often misapplied to specimens of the more widespread Monstera adansonii. What that tells you is that a label is not evidence, in either direction: it does not tell you what any individual plant is. Price is a useful secondary signal, since genuine obliqua trades among specialist collectors at prices an ordinary garden centre does not charge, but price is a fact about a seller, not a determination of a species.
What is a stolon and why does it matter for identifying obliqua?
A stolon is a long, leafless runner that grows out from the plant, travels some distance, and can root and form a new plant where it settles — think of a strawberry runner rather than a normal stem. Monstera obliqua is repeatedly described as producing them readily; Monstera adansonii is not. It matters because unlike leaf thinness or hole proportion, which are judgements about degree, a stolon is either there or it is not, and it is something you can observe on a plant you already own over a season rather than assess from a photograph.
Is "Monstera Peru" the same as Monstera obliqua?
Almost never, and this is one of the worst naming collisions in the houseplant trade. A plant sold simply as "Monstera Peru" is usually Monstera karstenianum — thick, glossy, deeply puckered leaves with no large holes at all, which nobody would confuse with obliqua if the names were different. Separately, collectors use "obliqua Peru form" for the extremely fenestrated plant they mean by obliqua. Two different plants, overlapping labels, and no way to resolve a specific listing without asking the seller what they actually have.
Is all Monstera obliqua highly fenestrated?
No, and this is the piece that most plant blogs leave out. Monstera obliqua as a species covers a wide geographic range and a number of forms, and the near-lace plant that collectors mean by the name is the form usually labelled "Peru". Other forms within the species are far less dramatic. So "more hole than leaf" identifies the form that is sought after; it does not define the species, and its absence does not by itself rule obliqua out.
How do you care for a Monstera obliqua?
It is not a beginner plant and it is not a normal houseplant. Leaves described as near-translucent have almost no capacity to hold water, so the plant is intolerant of dry air in a way that no other monstera is — and a heated Canadian home in January is close to the worst environment it could be placed in. People who succeed with it generally grow it in an enclosed case or terrarium, in a very open sphagnum-based medium, in bright indirect light, rather than on a shelf in a living room. Ordinary room conditions are the usual reason it fails.
Is Monstera obliqua toxic to cats and dogs?
Yes, like every monstera — insoluble calcium oxalate crystals in the leaves and stems, causing immediate mouth and throat irritation when chewed. In practice this species is usually grown in an enclosed case for humidity reasons, which happens to keep it out of reach, but the toxicity is the same as for a deliciosa or an adansonii.
Should I buy a plant labelled Monstera obliqua?
Buy it if you want the plant in front of you at the price being asked, and not because of the label. The name is documented as often misapplied, the trade labels overlap, and we are not in a position to authenticate a listing. Two questions are worth asking a seller: where the plant came from, and whether it has produced stolons. A seller who knows their material will answer both; one who cannot is selling you a label. If the plant is attractive and reasonably priced, an adansonii is an excellent houseplant on its own merits.