Monstera Obliqua vs. Adansonii - How to Tell Them Apart

Almost every plant sold as Monstera obliqua is, in fact, Monstera adansonii. The true Monstera obliqua is extremely rare, highly delicate, and primarily found only in the collections of dedicated aroid enthusiasts and botanists.

Here is a breakdown of how to tell the two apart, focusing on the visible characteristics that distinguish the rare obliqua from the common adansonii.

🔑 Key Identification Differences

The main difference lies in the leaf material and the amount of fenestration (holes). The true obliqua is more "hole" than leaf.

Feature	Monstera adansonii (Common)	Monstera obliqua (Rare Collector's Gem)
Rarity/Availability	Common. Sold widely in nurseries and garden centers.	Extremely Rare. Almost never sold commercially; only found through specialized collectors.
Leaf Thickness	Thick and slightly waxy (leathery) texture.	Very Thin and papery (almost transparent).
Fenestration (Holes)	The leaf surface is mostly leaf with small to medium-sized holes/fenestrations.	The leaf is mostly hole with a minimal amount of leaf surface remaining (often described as "lace-like").
Hole Shape	Holes tend to be oval/oblong and are neat and consistent.	Holes tend to be rounder and can be highly irregular, extending right to the edges.
Growth Rate	Fast. Will grow new leaves frequently and can quickly become a large vine indoors.	Painfully Slow. Growth is very slow, even in ideal conditions.
Growth Habit	Forms climbing or trailing vines.	Readily forms stolons (leafless runners) that search for a climbing surface. Adansonii does not typically form these runners.
Stem Thickness	Stems are noticeably thicker and sturdier.	Stems are incredibly thin, often around 2mm in diameter.

🔎 The Most Reliable Way to Tell Them Apart

If you have a plant labeled Monstera obliqua that you bought from a typical retail source, it is almost certainly a Monstera adansonii (likely a specific variety like the 'Narrow Form' or 'Wide Form').

To verify if you possess the true, rare Monstera obliqua, look for these two distinguishing features:

1. Leaf Material (The "Paper Test")

• True Obliqua leaves are so thin they are often described as being paper-thin or tissue-paper-like. They feel very delicate and almost appear transparent when held up to the light.

• Adansonii leaves are significantly thicker and more durable, with a more substantial, almost plastic-like feel.

2. Stolons (Leafless Runners)

• The true obliqua is known to send out long, leafless runners (stolons) that explore the ground or surrounding area before finding a vertical surface to climb.

• The adansonii does not produce these specialized leafless stolons.

⚠️ A Note on the "Monkey Mask" Name

The popular name 'Monkey Mask' is a commercial nickname that is almost always applied to a variety of Monstera adansonii, specifically one with very round, distinct holes. It is not a true species and is often incorrectly conflated with Monstera obliqua.

💚 Care and Cultivation Differences

The difference in rarity is directly tied to the difference in difficulty of care:

Species	Ideal Humidity Level	Indoor Suitability
Monstera adansonii	Tolerates normal household humidity (50%+)	Excellent houseplant. Tolerates average home conditions and is very forgiving.
Monstera obliqua	Requires extremely high humidity (80%+)	Difficult to maintain outside of a dedicated terrarium, grow tent, or greenhouse.

If your plant is thriving in average indoor conditions and growing quickly, you definitely have a fantastic Monstera adansonii!