Hydrocotyle verticillata, also known as Whorled pennywort, is a nice plant prized for its incredible vine-like growth, growth rate, versatility, and ease of care.
Whorled pennywort is capable of drastically improving the aesthetical quality of an aquarium when grown and maintained in the right manner.
Keep reading for everything there is to know about Hydrocotyle verticillata and how to cultivate and care for this plant in a home aquarium properly.
Quick Notes about Whorled Pennywort
| Common Name | Whorled pennywort |
| Other Names | Water pennywort, Whorled marsh pennywort, or Shield pennywort |
| Scientific Name | Hydrocotyle verticillata |
| Tank Size (minimum) | 10 gallons (~40 liters) |
| Difficulty | Medium |
| Lighting | Moderate |
| Optimal pH | 6.0 – 7.5 |
| Water hardness | Soft to moderately hard water (2 – 10) |
| Temperature | 68 – 82 °F (20 – 28 °C) |
| Substrate | Any |
| Can float: |
No |
| Can Be Grown Emersed: |
Yes |
| Growth Rate | Slow to moderate (submersed), moderate to fast (emersed) |
| Placement in Tank | Foreground / Midground |
| Fertilizer |
Recommended |
| CO2 | Not needed but recommended when submersed |
| Propagation | Lateral shoots (via runners) |
Interesting fact: Whorled pennywort is also used as a primary medicine for human ailments. This plant has therapeutic properties and is commonly used for fevers, wounds, boils, abscesses, colds, coughs, hepatitis, influenza, purities, sore throat, headaches, and urinary tract problems.
Origin of Whorled Pennywort
Hydrocotyle verticillata is a fast-growing stem plant species belonging to Hydrocotyle — a genus of prostrate, perennial, aquatic, or semi-aquatic plants.
The name Hydro is of Greek origin, meaning ‘water’, and Kotyle, meaning ‘small cup’ because of the leaves of certain species. The name Verticillatus came from the Latin meaning whorled, probably referring to the inflorescence.
Below is the scientific classification of Hydrocotyle verticillata.
Kingdom: Plantae
Phylum: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Apiales
Family: Araliaceae
Genus: Hydrocotyle
Species: Hydrocotyle verticillata
Habitat of Whorled Pennywort
Hydrocotyle verticillata is native to wet and boggy areas, in the Americas (from the USA to Argentina and Chile), tropical and subtropical Africa (from Somalia and Angola to South Africa). Nowadays this plant is well-spread in Australia, China, West Indies, and even Europe.
The plant grows in and around freshwater ponds, lakes, rivers, marshes, irrigation, and drainage canals, forming thick mats with long, creeping green stems.
| Important: Hydrocotyle verticillata species is often considered undesirable weed outside of their native distribution range. |
Description of Whorled Pennywort
Whorled pennywort is a flowering plant with small (0.07 inches or 2 mm across) greenish to creamy white color flowers. It flowers in clusters 6–12 in quantity.
This stem plant (measuring about 4 – 6 inches or 10 – 15 cm) features small, roundish, light green leaves (1 – 2 inches or 2 – 5 cm wide) above and pale beneath that grow on vine-like stems.
These leaves, resembling small lily pads, are arranged alternately along the stem. The leaves are almost completely round with no indentation.
Because of its unique, umbrella-like leaves and small size, Whorled pennywort leaves look like miniature, green mushrooms.
Hydrocotyle verticillata has a creeping growth habit owing to its vine-like stems (up to 10 inches or 25 long). This allows the plant to form a large mat on the water surface or along river banks and shorelines.
The species is highly versatile. Depending on the size of the tank, it can be utilized as a foreground or midground plant in freshwater aquaria, usually grown submerged in the tank or spread across the water surface.
Difference Between Whorled pennywort and Water pennywort
Whorled pennywort (Hydrocotyle verticillata) and Water pennywort (Hydrocótyle vulgáris) are often confused in the aquarium hobby. Both species are very similar and often hard to distinguish, however, Whorled pennywort is a much more vigorous counterpart of Water pennywort.
| Whorled pennywort (Hydrocotyle verticillata) | Water pennywort (Hydrocótyle vulgáris) |
|
| Veins | 9-13 | 7-9 |
| Petioles | Glabrous | With long patent hairs |
| Inflorescences | Longer than the subtending leaf |
Shorter than subtending leaf). |
| Size | Larger leaves and thicker stems. | A little bit slimmer |
Tank Requirements and Water Parameters
Whorled pennywort can grow in emersed or submerged environments that make this plant a great choice for paludarium setups.
Even more, in my experience, this plant grows much better in emersed environments; you can easily grow in a simple pot.
Tank size:
Whorled pennywort is a good fit for various tanks; thus, the species may be grown in any aquarium provided that it is not lesser than 10 gallons (~40 liters).
Note: For the nano tanks, I would choose Water pennywort (Hydrocótyle vulgáris). It grows smaller than Whorled pennywort.
Water type, Temperature, Hardness, and pH:
Temperature: Whorled pennywort will survive in temperatures between 41 – 86 °F (5 – 30 °C). However, ideal temperatures range for growing Whorled pennywort 68 – 82 °F (20 – 28 °C). Despite its subtropical origin, Whorled pennywort can easily stay alive even under cold temperatures. For example, this plant has a well-established population in Belgium where the annual mean temperature is around 50 °F (10 °C).
pH: The optimal pH range for growing this plant is 6.0 – 7.5. Whorled pennywort prefers slightly acidic water.
Hardness: Whorled pennywort does not like hard water. It will thrive in soft to moderately hard water, ideally between the range of 2 – 10 GH.
Lighting:
Contrary to what many websites say in the plant database, Whorled pennywort is very demanding in terms of light requirements. The difference will be in the growth rate and size of the plant.
For example, under low lighting conditions, Whorled pennywort will stand up and have a more vertical structure as if trying to reach the surface to get more light.
Whereas under high lighting, the plant grows short, generally, about 2 – 4 inches (5 – 10 cm).
Therefore, medium lighting intensity will be enough to thrive in your freshwater aquarium. Ensure to provide enough light and maintain adequate photoperiod of 8 – 12 hours daily
Related article:
Substrate:
Whorled pennywort does not have a strong root system. On the contrary, they are pretty small and delicate. Moreover, adventitious roots (which develop on the stem) can often grow even without any direct contact with the substrate. This is because Whorled pennywort is able to absorb nutrients directly from the water.
Therefore, there is no need for a nutrient-rich substrate like ADA Amazonia. Of course, it will be beneficial for the plant to grow optimally. Nonetheless, strictly speaking, Whorled pennywort can grow anywhere, including in sand and gravel if it has enough nutrition.
Note: Very fine sand substrates are not suitable for many plant species to avoid compacting and suffocating their tiny roots.
Related article:
CO2 and Fertilization:
CO2: CO2 supplementation is optional. At the same time, its growth rate will be painstakingly slow without CO2 in submerged environments.
Fertilization: On the other hand, regular fertilizer application is vital, especially when there are insufficient nutrients in the water to bolster the plant’s growth/development.
Also, dosing liquid plant fertilizers in the right amounts averts adverse effects often caused by nutrient deficiencies. Root tabs are not good for the Whorled pennywort.
Important: If you keep shrimp in the tank with Whorled pennywort, I would highly recommend reading my articles:
- CO2 in a Planted Tank Guide
- CO2 in a Shrimp Tank
- How Copper Affects Dwarf Shrimp
- Shrimp Safe Plant Fertilizers
The point is that a high level of CO2 and Copper (most fertilizers contain copper) is extremely dangerous to the shrimp.
Care and Maintenance of Whorled Pennywort
As I have already mentioned, Whorled pennywort can be grown emersed or submersed.
When grown emersed in high humidity conditions, the growth rate will be pretty fast. Whereas, if Whorled pennywort is submersed the growth rate will be slow to moderate. Depending on the CO2, nutrition, and lighting in the tank, it will grow a bit faster once established.
| Therefore, from all indications, caring for this species is not super easy, and that’s why it should not be a top pick for beginner aquarists. Unless you are going to keep it in a paludarium setup with free excess CO2. In this case, Whorled pennywort is one of the hardiest plants you can wish for.
If you like this plant but want something easier, check out Brazilian pennywort. |
Whorled pennywort tends to increase once established, necessitating regular pruning to maintain well-sized vegetation in the aquarium. To this effect, ensure you prune the plants every few weeks to get rid of overgrown stems — especially those growing on the foreground sections of the aquarium.
Regular pruning equally helps the Hydrocotyle verticillata attain a dense appearance, so you should prioritize this activity.
It’s also essential to maintain good water quality in the tank; through weekly partial water changes.
Furthermore, always test the aquarium water to keep abreast of significant changes in water chemistry (pH, kH, nutrient levels, etc.). In the same vein, be sure to dose liquid plant fertilizers in the water column from time to time; that way, the plants obtain adequate nourishment to thrive and stay healthy.
Planting and Propagation of Whorled Pennywort
Whorled pennywort is a highly versatile aquarium flora.
After proper disinfection, take the small stems and place them gently into the aquarium substrate. It is excellent for accentuating décors, e.g. driftwood, because of its vine-like growth.
Whorled pennywort spreads via runners. Creeping and horizontal stolens are grown connecting the plants. Therefore, this plant is propagated by cutting off the lateral shoots (with the leaf on it) and replanting them in the aquarium substrate or leaving them to float on the water surface.
I have noticed that when grown submersed, Whorled pennywort has a hard time recovering after cutting for propagation. It may take some weeks before you will see new runners.
Note: Dry start method can be another way to grow Whorled pennywort. This method will provide unlimited CO2. In the emersed state, it grows constantly and looks indestructible.
Related article:
Problems Associated with Whorled Pennywort
Sparse or leggy growth: This problem usually results from poor lighting conditions in an aquarium; here, your plants will struggle to maintain a fuller, healthy appearance. When the lighting intensity/output is too low, the plant may become leggy as the stems grow towards the tank’s surface.
Solution: Trim the stems to initiate new, dense growth; afterward, increase the lighting intensity for better light penetration.
Stunted growth: Stunted growth is often caused by various factors, including poor nutrient supply (too low nitrates), weak lighting output, deficient CO2 levels.
Solution: Ensure your live plants have ample nutrients (macronutrients and micronutrients), CO2, and increased lighting intensity to dwindle chances of witnessing abnormal growth.
Chlorosis: Chlorosis is a condition characterized by changes in the coloration of a plant’s leaves. The foliage of Whorled pennywort takes on a yellow coloration, especially at the edges due to insufficient amounts of iron (Fe) in the water column.
Solution: To remedy this condition, you are required to supplement the aquarium water with chelated iron, so the plants absorb enough to return to normalcy.
Melting: There is an emersed growth form of Hydrocotyle verticillata in the aquarium trade (identified with white flowers). These may die back in the aquarium before taking on a submersed form.
Solution: You don’t need to panic when you witness such an occurrence. It will grow back.
Benefits of Whorled Pennywort
Aquascape: Whorled pennywort will be an interesting decorative addition for aquascape. For example, even Mr. Takashi Amano used this plant in some of his aquascapes as a foreground plant. The most memorable use of Whorled pennywort was in the aquascape called “Grace of Angles” (AquaJournal Vol.18, December 1995).
Versatility: Whorled pennywort is one of a few plants that can be grown as emersed (terrestrial form).
Removal of excess nutrients: Whorled pennywort is highly dependent on nutrient availability in the water column. So, if you have some problems with nitrates, ammonia, and phosphates, this plant will help you in no time.
Firmness: Whorled pennywort does not “shed” leaves as many other floaters do.
Replacement: Even if it is rooted, the plant can be easily moved or removed. Whorled pennywort has very thin and delicate roots. You will not pull up a big part of your substrate with it.
Hiding place: Serves as cover and shade for invertebrates and small fish. It serves as a perfect hiding place for shrimp and fish.
Foraging place: Acts as a buffet of biofilm, which is an ideal first food for newly hatched fry and shrimplets.
Oxygenation: Whorled pennywort oxygenates and aerates the tank water.
Whorled Pennywort and Compatible Tankmates
This stem plant is compatible with a wide variety of aquarium pets:
- Fish (for example, Bettas, Swordtails, Tetras, Pearl Guorami, Honey Guorami, Harlequin Rasbora, Danios, Cherry Barbs, Platies, Guppies, Endlers, Mollies, Otocinclus Catfish, Pygmy Cory Catfish, etc.)
- Snails (for example, Japanese trapdoor snails, Ramshorn snails, Nerite snails, Malaysian Trumpet snails, Black Devil Snails, Asolene spixi, Rabbit Snails, etc.).
- Dwarf Shrimp (All varieties of Neocaridina (Red Cherry Shrimp, Blue Velvet Shrimp, Snowball shrimp, Black Rose, Orange Sakura, Green Jade, Rili Shrimp, etc) or Caridina species (for example, Crystal Red Shrimp, Caridina cf. babaulti, Blue Tiger Shrimp, etc.), Amano shrimp, Ghost shrimp, Bamboo shrimp, Vampire shrimp, ). Basically, you can keep any shrimp species with it. They will love it!
Avoid or Be Careful:
However, avoid keeping species like Goldfish, Silver dollars, Oscars, Jack Dempsey, Koi fish, and Buenos Aires Tetra since they won’t hesitate to devour the plant’s foliage. The same goes for large, aggressive fish like Cichlids that are capable of tearing the plant, damaging the stems, and dislodging its roots.
You can also read my article “Fish Causing Problems in Planted Tanks”.
Do not keep Whorled pennywort with most types of crayfish, or freshwater crabs. These animals will cut, eat, and uproot everything in the tank. So, be warned!
Buying Whorled Pennywort
The species is renowned and readily available in local fish stores and online stores. You can easily grab a pot or bunch of Hydrocotyle verticillata for $5-10; this typically contains about 5 – 7 stems.
Ensure you purchase plants that are fresh and healthy-looking, although not a guarantee that they will do well when cultivated in your aquarium. It’s always best to go for specimens in good condition.
The specimens’ likely signs of good health include fresh, light green leaves, upright stems, and abundant roots.
In Conclusion
Overall, Whorled pennywort is a good plant for beginners (if grown emersed) and other experience levels in the hobby.
The species is ideal for decorating fry and shrimp tanks and accentuating driftwood in the foreground ground of freshwater aquaria.
What’s more? Whorled pennywort be employed in adorning paludariums and terrariums; it’s suitable for various setups and aquascaping styles.
This plant can be housed in a low, medium, and high light and its size can vary depending on the light. Hydrocotyle verticillata is relatively hardy, undemanding, and adaptable to a wide range of water conditions, meaning that you don’t have to stress much to grow the species successfully in your aquarium setup.