Myriophyllum elatinoides, commonly known as Water Milfoil, is a popular, versatile aquatic plant species for decorating freshwater aquaria.
Water Milfoil is a relatively hardy plant suitable for beginners, characterized by fast growth and high decorative appearance.
In this article, I have compiled all the available information about Myriophyllum elatinoides, including the necessary conditions for its care.
Quick Notes about Water Milfoil
| Common Name | Water milfoil |
| Scientific Name |
Myriophyllum elatinoides (Myriophyllum quitense) |
| Difficulty | Easy-medium |
| Lighting | Moderate to High |
| Optimal pH | 6.0 – 8.0 |
| Optimal GH | 2 – 12 |
| Optimal Temperature | 68 – 79°F (20 – 26°C) |
| Substrate | any (can float) |
| Can Be Grown Emersed |
No |
| Growth Rate | Fast |
| Placement in Tank |
Midground or background |
| Aquarium size | 12 to 40 inches (60 – 100 cm) |
| Fertilizers |
Needed |
| CO2 | No |
| Propagation | Cuttings |
| Color | Green |
Etymology of Myriophyllum Elatinoides
The name “Myriophyllum” is derived from the Greek words “Myrio”, meaning “Numerous or many”, and “Phyllum” meaning “Leaf”.
The species name “Elatinoides” suggests a resemblance to plants in the Elatine genus. This term often signifies similarities in certain features.
Taxonomy of Water Milfoil
A key challenge for the genus Myriophyllum is the difficulty in distinguishing certain species due to their striking resemblance. For instance, based on еру study, it is suggested to consider using M. elatinoides as a synonym for M. quitense.
- Kingdom: Plantae
- Division (or Phylum): Magnoliophyta (Angiosperms)
- Class: Magnoliopsida
- Order: Haloragales
- Family: Haloragaceae
- Genus: Myriophyllum
- Species: Elatinoides / Quitense
Distribution of Water Milfoil
Myriophyllum elatinoides can be found in South America (Chile, southern Argentina), Mexico, the Falkland Islands, Tasmania, New Zealand, Australia, and China.
Habitat of Water Milfoil
This species generally occurs in irrigation systems and channel sites with high light availability and low water turbidity.
Description of Water Milfoil
With its bushy green foliage, Myriophyllum elatinoides makes an impressive background plant in the aquarium.
Distinguishing characteristics:
- Growth habit. Myriophyllum elatinoides is a perennial aquatic submersed or floating
- Size. It can grow very tall in the aquarium, typically reaching 12 – 40 inches (60 – 100 cm) high. The width is about 2 – 3 inches (5 – 7 cm).
- Stem. The stem is soft but relatively thick 0.1 – 0.2 inches (2 – 4 mm) in diameter.
- Leaves. The leaves are usually whorled, sometimes opposite, or alternate. Submerged leaves are 3- or 4-pinnate, rarely alternate, pectinate, ovate, or elongated. Emerging leaves are smaller, sometimes the uppermost undivided, reduced to bracts of the inflorescence.
- Color. The color range varies from pale green to emerald.
- Flowers. Myriophyllum elatinoides is a flowering plant. The inflorescence typically forms a terminal spike. The flowers are sessile, usually four-parted, small, with the lowermost being female, the upper ones male, and the intermediate ones bisexual. Male flowers have a deeply 2-4-lobed calyx; petals 2-4, boat-shaped, often pink; stamens 2-8, epipetalous. In female and bisexual flowers, the calyx tube is connected to the ovary; petals are small and often absent; stigmas are 4, sessile, curved, and feathery.
- Roots. The root system is weak.
Tank Requirements and Water Parameters
In order for this plant to show itself in all its beauty, certain requirements must be met.
Tank size:
Due to its significant size and very fast growth rate, Water Milfoil can only be suited in larger (high, especially) aquariums starting from 20 gallons (80 liters).
Water type, Temperature, Hardness, and pH:
Temperature: Although Myriophyllum elatinoides can grow even in cold water (down to 50°F or 10°C), the optimal temperature ranges from 68 – 80°F (20 – 26°C).
pH: This plant prefers water pH in the range of 6.0 – 8.0.
Hardness: It can grow in soft and hard water GH 2 – 12. However, it was also noticed that in soft waters it grows slower.
Lighting:
Water Milfoil requires at least medium-high lighting levels (30–50 PAR or 70–100 Lumens). Additionally, maintain a standard photoperiod of 10-12 hours daily.
It does not tolerate long-term shading well. With insufficient lighting, the stem elongates, becomes leggy, and density decreases.
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Flow:
Water Milfoil can tolerate moderate water movement, but avoid strong currents.
Substrate:
This plant mostly obtains nutrients from the water column. It does not require a nutrient-rich substrate since its root system is not well-developed.
CO2 and Fertilization:
CO2: Although CO2 addition promotes growth significantly, using a pressurized CO2 system is not mandatory. This is optional.
Fertilization: Myriophyllum elatinoides need moderate to high nutrient levels (especially phosphorus and nitrogen). Experiments showed that although phosphorus can be taken up through the leaves and through the roots, leaf uptake appears to be the preferential mechanism.
Therefore, regular dosing of liquid plant fertilizers (2-3 times a week) is required.
Note: If you keep shrimp in the tank with this plant Canadensis, 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.
Planting Water Milfoil
Myriophyllum elatinoides is a plant with long stems and is generally planted along the sides of an aquarium, in the midground, or background.
Also, do not plant the stems too close to each other (keep them at least 2 inches (5 cm) apart). In cramped conditions, this plant often drops its leaves.
You can use a pair of tweezers (link to check the price on Amazon) to gently place the stems into the substrate to avoid damage.
Features:
- Water Milfoil can be used as a floating plant or even tied to driftwood. If you leave this plant floating, it will find the place it likes and roots eventually.
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Propagation of Water Milfoil
This plant has vegetative propagation, specifically by cuttings.
Simply cut the upper portion of the stem with a pair of sharp scissors just above a leaf node. The ideal size of these cuttings should be 10 cm long (4 inches).
Afterward, make a hole in the substrate about 1 – 1.5 inches (3 – 4 cm), place the stems gently in the hole, and cover with the substrate.
In time, the healthy stems will develop roots and grow into new plants.
Problems Associated with Water Milfoil
Loss of leaves: This is an indication that your plant does not receive enough light. Additionally, if Myriophyllum elatinoides is cultivated too thick, the lower part suffers from a lack of light and that prompts it to shed the leaves.
Solution: To increase the light intensity, pull it all out and/or trim the plant when it appears to be getting quite dense, that way light will be able to reach all the parts.
Fragile. The stem might seem thick and hardy but in reality, it is pretty soft and can be easily broken.
Solution. Just be careful during maintenance.
Fast growth/ Overgrowth: Under high lighting, nutrition, and CO2, Water Milfoil can grow like a weed. It can completely fill up the tank within weeks. So, it will require a lot of trimming.
Solution: The plant will require regular stem trimmings to prevent it from overtaking the whole tank.
Discoloration: Changes in color may be triggered by nutrient deficiency (nitrogen (NO3) and phosphates (PO4)).
Solution: Regular feeding. Use liquid fertilizers periodically. Going forward, always test the tank water and ensure it holds ample nutrients to promote optimal health and development of the plants.
Related article:
- How to Spot Nutrient Deficiencies in Aquatic Plants
- Everything about Nitrates in Planted Tanks
- Phosphates in Freshwater Tanks
Benefits of Water Milfoil
Aquascape: The shape and form of Myriophyllum elatinoides can be an excellent decorative addition to the jungle or Dutch style aquascapes.
Hiding place: Serves as cover and shade for inverts and small fish.
Foraging place: Acts as a buffet of biofilm, which is an ideal first food for newly hatched fry and shrimplets.
Reduces nitrates: Because of its fast-growing rate, Myriophyllum elatinoides acts as a sink for nutrients such as phosphorus and nitrogen. It has been reported to efficiently remove nutrients, heavy metals, and organic contaminants.
Reduces algal bloom: This plant is so greedy for nutrients that it simply outcompetes algae and cyanobacteria (allelopathic interactions).
| According to the study, the biomass of Myriophyllum elatinoides can be utilized as a high-quality feed for livestock and poultry as it contains high concentrations of nutrients such as protein. |
Quarantine Water Milfoil
Unless you are completely sure that Myriophyllum elatinoides is safe, for example, it was grown in sterile/laboratory conditions (in vitro) and the in vitro pot is not damaged or opened, do not forget to quarantine and disinfect it first to avoid the risk of contamination and poisoning.
DO NOT introduce a new plant to your tank right after you bought it.
- The plant can have parasites, pests like snails, or even predators (dragonfly, damsefly nymphs, etc.).
- It may already contain residues of chemicals (pesticides) to remove parasites, snails, etc. These chemicals are extremely poisonous to fish, shrimp, and other invertebrates.
To find out more, read my articles:
In Conclusion
Myriophyllum elatinoides is a beautiful and easy-to-grow stem plant that requires medium to strong lighting to thrive.
This fast-growing plant can grow in all kinds of substrate (even floating), without CO2, and quickly adapts to almost any conditions. Additionally, this plant absorbs nitrates like a sponge!
At the same time, it should be noted that many of these advantages can, over time, become a burden for the aquarist because this plant, without proper control, can overshadow everything it can.
References:
- Xia, Jingye, Tianwei Hua, Yuan Xue, Lejun Zhao, Hongwen Sun, and Chunguang Liu. “Myriophyllum elatinoides: A potential candidate for the phytoremediation of water with low level boron contamination.” Journal of Hazardous Materials401 (2021): 123333.
- Li, Xi, Yuyuan Li, Yong Li, and Jinshui Wu. “Myriophyllum elatinoides growth and rhizosphere bacterial community structure under different nitrogen concentrations in swine wastewater.” Bioresource technology301 (2020): 122776.
- Orchard, A. E. “A revision of South American Myriophyllum (Haloragaceae) and its repercussions on some Australian and North American species.” Brunonia4, no. 1 (1981): 27-65.
- Li, YuYuan, Xi Li, JinShui Wu, KuanYi Li, and WeiBo Wang. “Regional adaptability and ecological competitiveness of Myriophyllum elatinoides in mainland China.” Journal of Agro-Environment Science37, no. 10 (2018): 2252-2261.
- Orchard, A. E. “Myriophyllum (Haloragaceae) in Australasia. 1. New Zealand: A revision of the genus and a synopsis of the family.” Brunonia2, no. 2 (1979): 247-87.