Cryptocoryne Undulata: From Care to Propagation

Cryptocoryne undulata is an aquatic plant that belongs to the genus Cryptocoryne and family Araceae. With its ruffled, undulating leaves that can grow up to 14 inches long, Cryptocoryne undulata adds drama and interest to aquariums and paludariums.

This species is native to Sri Lanka and Thailand, where it grows along streambanks and in swampy areas. Cryptocoryne undulata thrives with bright, indirect light and warm water temperatures between 72-82°F. Though not the easiest cryptocoryne to find, those who acquire it are rewarded with a uniquely shaped, vibrant plant.

In this complete guide, we will explore Cryptocoryne undulata in depth, covering topics such as:

  • Taxonomy and classification
  • Physical description
  • Native habitat
  • Cultivation and care
  • Propagation
  • Interesting variants
  • Comparisons with similar species
  • Frequently asked questions

Let’s dive in and unravel the mysteries of this magnificent aquatic plant.

Taxonomy and Classification

Cryptocoryne undulata belongs to the genus Cryptocoryne, which comprises over 50 species of aquatic plants native to Southeast Asia. The genus name comes from the Greek words “kryptos,” meaning hidden, and “koryne,” meaning club, referring to the shape of the plant’s flower.

Initially, Cryptocoryne undulata was considered a form of the similar C. willisii species. However, recent taxonomic studies have established it as a distinct species.

The accepted scientific classification is:

Kingdom: Plantae
Division: Angiosperms
Class: Monocots
Order: Alismatales
Family: Araceae
Genus: Cryptocoryne
Species: Cryptocoryne undulata


In the past, Cryptocoryne undulata has been published under the following synonymous scientific names:

  • Cryptocoryne willisii var. undulata Engler ex Baum
  • Cryptocoryne axelrodii Rataj

The currently accepted name is Cryptocoryne undulata de Wit.

Physical Description

Cryptocoryne undulata is an amphibious plant that can grow fully submerged or emersed. The leaves will be thinner and more translucent when grown underwater than above water growth.


The most striking feature of Cryptocoryne undulata is its leaves. The leaves are a dark green, with ruffled edges that give them an undulating appearance. The leaves range from 8-14 inches long when the plant matures. They emerge from the base of the plant in a rosette pattern.


The stems of Cryptocoryne undulata are short, limiting the height of the plant to under 12 inches. Occasionally, runners will extend from the base to allow the plant to propagate vegetatively.


A healthy root system is vital for Cryptocoryne species. C. undulata forms numerous thin roots that anchor it into the substrate.


Cryptocoryne undulata will flower when happy. The flowers consist of a greenish spathe surrounding a spadix. The spathe eventually opens to reveal the true flower. Pollinated flowers will be followed by berry-like fruit. However, flowering underwater is uncommon.

Distribution and Habitat

Cryptocoryne undulata hails from the tropical forests of Sri Lanka and Thailand. It grows in the wild along streams, rivers, and swampy areas. Conditions are humid and shaded in its natural habitat.

Here are some details on the native distribution:

  • Sri Lanka – Occurs mostly in the southwestern wet zone regions. Found growing along waterways in the rainforest understory.
  • Thailand – Scattered localities within Thailand. Often found in peat swamp forests and wetlands.

Cryptocoryne species inhabit transitional zones between land and water in the tropics. Their ability to grow submerged or emersed allows them to thrive in fluctuating water levels.

Biotope Aquariums

Aquarium hobbyists often try to replicate the natural habitats of aquatic plants and fish in a biotope setup. For Cryptocoryne undulata, collect materials such as:

  • Peat, leaves, muck from swamps
  • Aged driftwood

Use a gentle water flow and low-nutrient substrate to mimic its oligotrophic native waters. A splash of terrarium plants like ferns or orchids completes the biotope.

Cultivation and Care

While not the easiest cryptocoryne, Cryptocoryne undulata is less demanding than some of its cousins when cared for properly. Success with this species boils down to providing suitable water conditions, nutrition, lighting, and substrate.

Water Conditions

  • Temperature: 72-82°F (22-28°C). C. undulata enjoys warm tropical temperatures. Cooler temperatures below 68°F can cause the leaves to rot.
  • pH: 5.5-7.5. Acidic, neutral and slightly alkaline water are all fine. But aim for the lower end of the range.
  • Hardness: 1-15 dGH. Soft to moderately hard water is suitable. Avoid extremely hard water above 15 dGH.
  • Flow: Gentle flow mimics the sluggish streams of its habitat. Fast currents can damage the leaves.


Cryptocoryne undulata grows best in bright, indirect light. Here are some lighting guidelines:

  • Intensity – Moderate to high. 30-80 micromoles is ideal for vibrant growth.
  • Duration – 10-12 hours per day. Long photoperiods promote growth.
  • Type – Cool white or full spectrum fluorescent/LED lighting.

Without sufficient light, the leaves can become long and leggy. Place in a spot with lots of ambient daylight.


Use a nutrient-rich substrate to support healthy crypt growth. Some good options include:

  • Soil substrates high in organics like ADA Aqua Soil
  • Sand/gravel mixes with added root tabs
  • Coconut coir, peat, compost also work well

A depth of 2-3 inches allows room for the roots to spread out. Maintain low-nutrient water to promote root uptake.


While Cryptocoryne undulata grows slower than stem plants, it still benefits from added nutrients. Use a liquid fertilizer to provide macronutrients like:

  • Nitrogen
  • Potassium
  • Phosphorus
  • Iron

Root tabs placed near the base supply micronutrients and trace elements. Perform regular water changes to replenish minerals eaten by plants.


Basic maintenance is required to keep C. undulata looking its best:

  • Wipe leaves to remove algae and debris
  • Remove old leaves at the base as they die off
  • Thin dense growths to improve light penetration
  • Prune any leggy growth above 12 inches
  • Replant runners to propagate

With the proper setup and care, Cryptocoryne undulata will flourish. Now let’s look at propagating this amazing plant.


There are several techniques to propagate Cryptocoryne undulata within the aquarium:


This plant produces runners laterally from the main crown. The runners will eventually form a small daughter plant. Detach the runner and replant once it has developed roots and leaves.

Rhizome Division

Carefully uproot the plant and divide the rhizome into smaller sections using a clean knife or scissors. Replant each rhizome segment to create new plants.

Tissue Culture

Lab-cultured tissue culture plants are available from specialty nurseries. These plants are disease-free but more expensive.


Collecting and germinating the seeds from a flowering Cryptocoryne undulata is possible. But this is a very slow process.

Patience is needed, as Cryptocoryne species are slow growers. But propagating C. undulata helps to perpetuate this uncommon beauty.


Cryptocoryne undulata has produced some interesting color forms and cultivars over the years. Here are some of the most popular variants:

Cryptocoryne undulata ‘Broad Leaves’

As the name suggests, this variant has broader leaves than the wild type. The leaves are also more ruffled in appearance.

Cryptocoryne undulata ‘Green’

The green morph has leaves that remain a brighter, light green color. It does not develop the darker green leaves of the normal C. undulata.

Cryptocoryne undulata ‘Kasselmann’

Named after the famous crypt botanist, this is a rare form collected by Kasselmann himself. Shorter, more undulated leaves characterize it.

Cryptocoryne lucens

Though formerly confused with C. undulata, this Southeast Asian species is now recognized as distinct. Cryptocoryne lucens has reddish leaves and a more compact growth habit.

Comparisons With Similar Species

Cryptocoryne undulata is often confused with the following lookalike species:

Cryptocoryne wendtii

Cryptocoryne wendtii is one of the most popular crypts in the aquarium trade. But it differs from C. undulata in several ways:

  • Leaves are green to brownish, not dark green
  • Only reaches a maximum height of 6-8 inches
  • Easy to moderate growth difficulty
  • Found in different parts of Sri Lanka

Cryptocoryne parva

While C. parva has ruffled leaves like C. undulata, they are much smaller (under 4 inches). Cryptocoryne parva also remains more compact.

Cryptocoryne retrospiralis

These species both have undulated leaves. But C. retrospiralis has distinctive spiraling and curling leaves. Cryptocoryne retrospiralis is uncommon in the hobby.

By understanding the similarities and differences with other crypt species, aquarists can better identify and care for Cryptocoryne undulata.

Frequently Asked Questions

What is the common name for Cryptocoryne undulata?

The most frequently used common name is undulate cryptocoryne. It describes the ruffled appearance of the leaves.

How can I differentiate Cryptocoryne undulata from Cryptocoryne wendtii?

C. undulata has darker green, longer leaves that can reach 14 inches. C. wendtii is shorter with green to brown leaves just 6-8 inches tall.

Is Cryptocoryne undulata suitable for beginners?

While not the absolute easiest cryptocoryne, C. undulata’s moderate growth requirements can be handled by aquarists of all experience levels. It’s less demanding than notoriously tricky crypts like C. beckettii.

What is the growth rate of Cryptocoryne undulata?

Cryptocoryne undulata is a relatively slow growing species. You can expect leaves to reach their maximum length within 8-12 months. Faster growth is achievable with excellent conditions.

Can Cryptocoryne undulata be grown emersed?

Yes! Cryptocoryne undulata will transition from submerged aquatic growth to emersed growth above water when kept in a very wet environment. The leaves become shorter and more oval shaped when grown emersed.


From its gracefully undulating leaves to its Southeast Asian origins, Cryptocoryne undulata is an aquatic plant shrouded in mystique. As one of the more unusual members of the Cryptocoryne genus, C. undulata offers a departure from the ordinary. This plant brings drama to aquarium displays with its rippling, ruffled foliage and adaptations to wetland environments.

Yet, Cryptocoryne undulata remains accessible enough for cultivating by regular aquarists when provided with bright, humid conditions. Its ability to grow submersed, emersed or anywhere in between demonstrates the versatility of this amphibious species. For those looking to add an extra dimension to their aquarium, Cryptocoryne undulata’s flowing contours will certainly fit the bill.