Rotala rotundifolia is a beautiful and unique aquatic perennial plant that grows very successfully in home aquariums, water gardens, and backyard ponds. Originally native to Southeast Asia, Rotala rotundifolia translates to “the plant with the round leaves,” but these round leaves are only present in its wetland, semi-aquatic creeping form; the more terrestrial form of this plant has more oblong leaves. Interestingly, it is also sometimes referred to by the common names “roundleaf toothcup” and “dwarf rotala.”
Within its native range, Rotala rotundifolia can be found most commonly growing on the margins of wetland rice paddies and other areas that have standing water or high moisture content. Because of its easy manageability and attractive appearance, this plant is a great option for novice and experienced people alike! Rotala rotundifolia has been a popular plant of choice within the aquarium industry for many years all over the world, and is becoming more prevalent for water gardens and ponds over time as well.
Rotala rotundifolia is a creeping plant that has soft stems with dark pink coloration. The leaves of this plant, when grown in wet environments, are round in shape and attach to the stem closely without a leaf stalk. Rotala is known for its high level of phenotypic plasticity, and may vary greatly in appearance and form depending on the environmental conditions in which it is growing.
While it is not native to the United States, Rotala rotundifolia has been introduced there and is considered an invasive species in some areas, particular southern states like Florida. In other areas in the United States, it has become a naturalized part of the ecosystem. It has become established in parts of Florida and Alabama, with potential to reach Mississippi. While it is considered a pest in the areas it has become invasive, within its native range Rotala rotundifolia is widely used as a medicinal plant!
Facts, Benefits & Uses of Rotala
Rotala rotundifolia can be used effectively for bioremediation purposes. It has the ability to effectively remove nitrogen and phosphorus in eutrophic waters, helping to clean the body of water in which it is growing. Eutrophication is the result of excessive nutrient accumulation in water, and can result from runoff of agricultural land, sewage, and industrial waste. These nutrient accumulations can lead to rapid algal growth and, subsequently, elimination of oxygen and the death of fish and other aquatic organisms. Growing plants like Rotala in eutrophic waters can help to offset these detrimental effects.
Within its native range of Southeast Asia, southern India and Japan, Rotala rotundifolia is commonly used for medicinal purposes. The species is known for its antipyretic properties, which help to reduce fevers. It can also help alleviate swelling and aid in detoxification. In China, it has many uses – people utilize Rotala to treat cirrhosis, gonorrhea, menstrual cramps, and even piles.
It is widely assumed that Rotala rotundifolia is pollinated by insects, but there is little information regarding which pollinators this plant attracts. It does not appear to require specialist pollinators, but this is uncertain as well. With small, vibrant pink flowers, it can be reasonably assumed that bees, moths, and butterflies would be at least somewhat drawn to this plant.
Rotala Growth, Hardiness & Climate
Rotala rotundifolia has been found to grow optimally in silty soil as compared to sand or gravel. That being said, it can still grow successfully in sandy or gravelly soil. Its adaptability is one feature that makes this plant so attractive to pond and aquarium owners alike! While it grows optimally in tropical, warm temperatures between 20 – 28 °C (68 – 82 °F), this plant is pretty hardy and can thrive in a wide range of other temperature conditions as well.
Rotala rotundifolia can grow at an incredible rate of 4-5 inches per week (10-12 centimeters). It will grow across the water’s surface, and it can also spread out via floating stem fragments that can take root at the node. Each plant can produce viable seeds as well. The stems of Rotala can grow to be up to 16-20 inches in height (40-50 centimeters). Due to this, Rotala is often regarded as a nuisance plant, as it grows so quickly and can be difficult to control.
In the spring and summer months, Rotala rotundifolia begins to flower. When this plant blooms it produces beautiful purple to pink colored flowers atop any stalks that are above the water. Submerged parts of the plant will not produce flowers.
How to Plant Rotala In Ponds
While Rotala looks beautiful when growing in clump formations, it is important to leave enough space between each stem when planting it in your aquarium or pond.
It is very simple to plant Rotala in your aquarium or backyard pond. Simply place your plant directly into a shallow gravel pocket and nature will take care of the rest! While it is very easy to grow Rotala rotundifolia, it is also very easy to let it over grow. To avoid this, be sure to regularly trim and prune your plants to prevent them from taking over your space. When you cut your plants, be sure to remove the cuttings to prevent them from taking root and propagating.
Rotala can propagate in one of two ways- it can be replanted via its head cuttings, or it can also grow by ‘running.’ It can grow in a wide range of water depths- anywhere between 2 – 24 in (5 – 61 cm) as long as the water is clear so that it can still receive adequate amounts of sunlight.
Using a tray or basket to plant your Rotala in can make it much easier to maintain and contain your plants over time – otherwise, they can easily grow very rapidly and become invasive in their environment. However, with regular trimming and close observation, you can successfully plant your Rotala straight into your aquarium, pond, or water garden without the need of a basket or tray.
How to Care For Rotala
Caring for Rotala rotundifolia is incredibly easy and straightforward! It grows at a fairly rapid pace, so it is important to prune it in order to prevent the plant from becoming too bushy or outcompeting your other plants. Cutting your Rotala once in a while will also help to ensure that there is enough spacing between individuals, and prevent overcrowding. Removing cuttings and dead sections of the plant is also very important. If you leave the cuttings in the water, they can easily take root and begin growing another unwanted plant. This defeats the purpose of pruning!
How to Winter Rotala
If you are growing Rotala in your aquarium, the temperature is regulated and there is no need to take any action in the wintertime! If you are growing it in an outdoor water garden or pond, however, you will notice some changes in your Rotala as the temperatures drop!
The good news is, you don’t have to go to any trouble to overwinter your Rotala rotundifolia, even if it is growing outside. When the colder months roll around, Rotala rotundifolia will produce its own buds that are capable of surviving the winter at ground level. While the roots, stems, and leaves will all die off at the end of the growing season, the buds will lay dormant until temperatures warm up again. You will notice that it comes right back in the springtime!
Is Rotala Toxic, Poisonous or Invasive?
Outside of its native range of southeast Asia, southern India and Japan, Rotala rotundifolia has been introduced and become an invasive species in some areas. It has become naturalized in Australia, Hungary, and the United States. In these countries, there are regions where Rotala rotundifolia can reproduce, maintain itself, and spread without any assistance from humans.
Is Rotala Edible? Will Fish Eat it?
If you own an aquarium or a pond with fish in it, Rotala rotundifolia is an excellent choice of aquatic plant to add to the habitat. It is easy to maintain, hardy, and non-toxic to your fish friends if they choose to eat it. It grows relatively fast, so most fish will not eat it to the point where it cannot recover. It is also compatible to keep with shrimp or snails in an aquarium or pond setting.
Fish have been seen attempting to eat Rotala rotundifolia, and then proceeding to spit it out. However, it is not known to be a toxic plant for fish, livestock, or pets.
Aquarium fish love to swim among jungle-like plants like Rotala rotundifolia as it gives an element of excitement to their habitat. Having fresh plants in the aquarium alongside your fish also improves their quality of life!
Where to Buy Rotala & Seeds? (UK & US)
Rotala is an affordable aquatic plant, and can be found at most pet and aquarium stores for under 5 USD (3.59 GBP), or via online retailers for around the same price. When you are purchasing Rotala in person, make sure that the leaves are bright green or reddish in color to ensure that you are getting a healthy plant. Adding a healthy plant to your aquarium will increase the likelihood that it will root and thrive in its new environment.
Before adding the new addition to your aquarium, be sure to wash it thoroughly and give it a ‘quarantine’ period in its own separate container. This will help to ensure that it is free of parasites or chemicals that can wreak havoc on your fish or other plants.
