Monstera Adansonii vs. Obliqua: How to Tell If Your Monstera Obliqua Is Real

Look at the leaf texture and the stem, not the number of holes. According to the botanical description, Monstera obliqua has thin, membrane-like leaves mostly 3 to 6 inches (8–15 cm) long, a stem only a few millimeters thick, and holes (when it has any) in a single row along each side of the midrib. Monstera adansonii has firmer, slightly leathery, glossy leaves, a thicker stem, and on mature leaves several rows of holes. A lacy, hole-filled leaf doesn’t prove you have an obliqua: most plants of that species have no holes at all.

Monstera adansonii vs. obliqua at a glance

	Monstera adansonii	Monstera obliqua
Leaf shape	broadly ovate to elliptic; RHS: heart-shaped	variable, mostly ovate and slightly sickle-shaped, with a lopsided base
Holes	none to many; mature leaves can have several rows per side	about 80% of specimens have none; otherwise one to many holes in a single row per side
Leaf texture	slightly leathery, glossy on top	thin, membrane-like
Leaf length (mature wild plants)	10–28 in (25–70 cm)	mostly 3–6 in (8–15 cm)
Mature stem	0.6–1.2 in (1.5–3 cm) thick	2–7 mm thick
Growth indoors	fast (NC State)	slow (RHS)
Availability	common houseplant	rare in cultivation (RHS)
Care	bright indirect light, moderate to high humidity	bright indirect light, moderate to high humidity
Pet toxicity	toxic to cats and dogs (NC State); ASPCA: Monstera genus toxic	ASPCA: Monstera genus toxic; RHS: harmful if eaten

The leaf and stem measurements come from Michael Madison’s 1977 revision of the genus Monstera and describe mature plants in the wild. Houseplants are usually smaller; NC State notes that adansonii leaves stay smaller indoors than in the wild.

How to tell if a Monstera obliqua is real

No single trait settles it. Look for several at once:

1. Leaf texture. Madison describes the obliqua leaf blade as membranaceous, meaning thin like a membrane. He describes adansonii leaves as subcoriaceous (slightly leathery) and glossy on the upper surface. You can feel the difference: an obliqua leaf is thin, an adansonii leaf is firmer.
2. Rows of holes. On obliqua, any holes sit in one row on each side of the midrib. Mature adansonii leaves can have holes in several rows. Young adansonii leaves may have no holes at all, so this check works best on larger leaves.
3. Stem. A mature obliqua stem is 2–7 mm thick; a mature adansonii stem is 1.5–3 cm (about 0.6–1.2 in). Obliqua is a small vine overall, with leaf stalks 2 to 6 inches (5–15 cm) long, compared with 8 to 24 inches (20–60 cm) on adansonii.
4. Flowers. This is the botanist’s test, since container plants rarely bloom (the RHS says so for obliqua). Obliqua usually produces six to eight inflorescences in a cluster, each with a small, bright yellow spathe about 1.5 to 3 inches (4–7 cm) long. Adansonii has a cream to pale yellow spathe 5 to 11 inches (12–28 cm) long.

The lopsided leaf base that gave obliqua its name (Latin for “oblique”) won’t help you. According to Madison, Monstera adansonii subsp. laniata, one of the adansonii forms, also has a very unequal leaf base.

How many holes does Monstera obliqua have?

Social media shows obliqua as a leaf that is “more hole than leaf.” The botanical record tells a different story. Madison examined herbarium specimens from across the species’ range and found that about 80% had entire leaves with no holes. The rest ranged from slightly to heavily perforated. Plants with perforated leaves were once described as a separate species, Monstera expilata; Kew’s Plants of the World Online now treats that name as a synonym of M. obliqua. Madison found no geographic or ecological pattern in the perforated forms, except that they are absent from Panama.

For buyers, that means two things:

• Lots of holes doesn’t mean obliqua. Adansonii is highly variable, and its leaves can have many holes.
• Few holes doesn’t rule obliqua out. Most true obliquas have solid leaves.

We couldn’t find a reliable hole-to-leaf percentage in botanical sources that could be used for identification, so we don’t quote the figures that circulate online.

Why are so many “Monstera obliqua” plants mislabeled?

Part of the answer is simple name confusion in the trade. The RHS plant database shows it clearly: the cultivar ‘Monkey Mask’ appears both as Monstera obliqua ‘Monkey Mask’ and as Monstera adansonii ‘Monkey Mask’. The same plant on sale carries two different species names.

Availability adds to it. The RHS describes Monstera obliqua as a rare, slow-growing, compact plant that takes 10 to 20 years to reach full size. NC State Extension describes adansonii as fast-growing and easy to grow. Madison called adansonii the most widespread, most common, and most variable species in its group, and noted that its subsp. laniata even grows on fence posts and roadside trees.

Obliqua isn’t rare in nature, though. Madison called it the only Monstera species that is abundant in the Amazon Basin, where it grows as a tiny vine along waterways. It is rare in cultivation, where the RHS notes it grows slowly.

So if you see a fast-growing vine with oval holes and firm, glossy leaves, every one of those traits matches the description of adansonii, whatever the label says.

What to check before buying a Monstera obliqua

For general advice, read our guide to buying rare houseplants. For obliqua specifically:

• Ask for photos of the leaf and a close-up of the stem. A thin, membrane-like leaf and a stem only a few millimeters thick are good signs. A thick stem and leathery, glossy leaves point to adansonii.
• Ask to see several leaves. Obliqua leaf shape varies a lot between plants, but a few leaves side by side show texture and the number of hole rows better than one hand-picked leaf.
• Ask where the mother plant came from and who identified it. A seller who knows nothing about the plant’s origin has no way to back up the name.
• Watch for cultivars sold under two names. As ‘Monkey Mask’ shows, the species name on a label may just be trade habit.

None of these traits gives full certainty on a plant that isn’t flowering. Botanists separate the species mainly by their flowers and fruit.

Is Monstera adansonii var. laniata a different plant?

According to Kew’s Plants of the World Online, both species are accepted:

• Monstera adansonii is native to tropical America, from Nicaragua to Bolivia and Brazil and the Lesser Antilles. Kew accepts subspecies of it, including subsp. laniata and subsp. klotzschiana. Madison described them as varieties in 1977 (var. laniata, var. klotzschiana); the current subspecies names were published by Mayo and Andrade, and the old variety names are now synonyms. Monstera pertusa is also a synonym, and the RHS lists it that way too.
• Monstera obliqua is native from Costa Rica to tropical South America and Trinidad. Its synonyms include Monstera expilata and Monstera falcifolia, names originally given to different leaf shapes.

In practice, a plant labeled “var. laniata” is still Monstera adansonii, not a separate species.

Does Monstera obliqua need different care than adansonii?

The RHS gives both species the same basics: grow them indoors or under glass in bright indirect light, with moderate to high humidity, in a peat-free, loam-based potting mix. Both need a minimum of about 50–59 °F (10–15 °C). Water freely during the growing season and feed monthly with a balanced liquid fertilizer. In winter, the RHS says to keep obliqua just moist and to water adansonii sparingly.

For adansonii, NC State adds that it prefers high humidity and suggests a humidifier or a tray of wet pebbles. See our full Monstera adansonii care guide for light, watering, and propagation.

Are Monstera adansonii and obliqua toxic to pets?

The ASPCA, the standard reference for pet toxicity, doesn’t list either species on its own. In an article on troublesome houseplants, though, it names the whole Monstera genus among plants containing insoluble calcium oxalates, so treat both as toxic to pets. It also lists their relative Monstera deliciosa as toxic to dogs and cats because of insoluble calcium oxalates, with signs such as mouth irritation, drooling, vomiting, and difficulty swallowing.

• Adansonii: NC State Extension lists it as a problem for cats, dogs, and children. It contains calcium oxalate crystals, and eating it can cause inflammation of the mouth and throat, drooling, vomiting, and loss of appetite. The sap irritates skin.
• Obliqua: There’s no species-specific pet entry, so the ASPCA’s genus-level listing is the best data available. The RHS adds that it is harmful if eaten, irritates skin and eyes, and should be handled with gloves. Keep it away from pets like any other monstera.

For more plants to keep out of reach, see houseplants toxic to cats and dogs.