Rotala


(Unedited version)
Originally appeared in the January 2009 issue of
Tropical Fish Hobbyist Magazine

Incredible colors from dark magenta, to golden yellows, and lush greens paint aquarium plants from the genus Rotala. Their striking colors combined with multiple leaf shapes have made them a popular plant for the aquatic gardener.

The genus Rotala has been known for some time, and three botanists are responsible for most of what we know about the species. The description from the type species, R. verticillaris, is ascribed to Carl von Linné in 1771. More extensive work was done on the genus by the leading authority on the family it belongs to, Lythraceae, by German botanist Bernhard Adalbert Emil Koehne in the late 1800's. And the most recent work from Christopher D. K. Cook in 1979.

With the heightened interest in aquarium plants in recent years, more plants are being imported. Among these are new species, and new variates, and new crosses. It's no wonder that there is some confusion on the naming of some of these plants, and Rotala has a long history of name confusion. Needless to say there is some difference in sources on the number of species. Cook claimed there were 44 species in 1979. Lists on line indicate more than 100 but these include variations (commonly called misspellings) in the same names and variates. I noticed that these lists are also missing some of the species names I've seen in aquarium circles. Which ever way you look at it there are a lot of potential aquarium plants in the genus Rotala. We'll look at a few of those you're more likely to encounter in the aquarium hobby.

Rotala indica

This plant may not be what you think it is. Apparently this is one of those instances where someone goofed at some point 40 some years ago, and since most of us just couldn't possible have known better, we've been giving the wrong plant the wrong name ever since. The real R. indica was rarely seen in the hobby previously but is starting to become more available in recent years. If you can't find it locally you may be able to find someone selling it on line or at an aquarium plant event, club or convention. The USGS web site mentions that this plant was introduced with rice seeds and grows as an annual in California and Louisiana near the rice growing regions.

Rotala rotundifolia

Rotala rotundifolia is the relatively easy to grow Rotala that's been mistakenly known as R. indica in the aquarium trade for many years.

This is one of the plants that did well for me when I really started to explore beyond the classic aquarium plants in the late 1980's and early 90's. It's among the easiest to grow of the stemmed plants and particularly among red stemmed plants.

Rotundifolia refers to the round leaves that grow out of the water when the plant grows wild. In the aquarium the leaves are long and somewhat narrow.

This plant will grow in moderate lighting in a relatively simple set up, though higher light levels and additional fertilization can give you more impressive results. You will need good lighting to get the best colors out of R. rotundifolia. If you make this plant happy it will reward you with attractive, red, pink , or gold leaves. It will send out side shoots in good growing conditions.

You can trim stems and replant to fill your aquascape or to share, trade or sell. If you allow the stems to reach the top of the tank the growth form will change somewhat. Leaves will face up along the stem growing on both sides as it floats at the surface of the tank water. At this point the plant will also tend to start sending roots down from the stem too. Though it obviously does naturally I've never gotten it to grow up out of the tank, I've only gotten the floating stems.

Originally from Southeast Asia, southern India and Japan. It will grow in the wild both in and out of the water in damp soil. Large clusters of the plants send many pink flowers on terminal spikes. According to the USGS it has been introduced in both Florida and Alabama. There are some concerns it may spread and become another destructive invasive weed. It is often compared to purple loosestrife, another plant in the same family that has become a problem plant in almost every state.

Rotala macrandra

When growing emersed R. indica, rotundifolia, and macrandra, can be difficult to distinguish from one another. Underwater it's whole different story. R. macrandra is a beautiful and highly sought after aquarium plant. This gorgeous plant has red ruffled leaves. These can vary from shades of purple to orange, depending on the plant and growing conditions.

These plants are from Southern India and often located in water with a fast moving current. In the aquarium they can be very difficult requiring a clean, well lit, aquarium with strict attention to fertilizers and CO2. The stems are delicate and often rot, making it difficult to establish. It may also be sensitive to some aquarium medications. That said if it is happy it can grow very well. The leaves are beautiful and side shoots will grow making the plant very full. It can grow up to about 2 feet tall. When this plant is healthy it's very impressive.

There are a number of plants being sold as R. macrandra (narrow leaf, green, magenta, variegated, colorata, etc.) Some of these are being sold even more confusingly as, for example R. magenta. It's somewhat uncertain what exactly these plants are and may be several things, natural, or cultivated varieties of the same plants, hybrids, or different species. Those plants labeled as green and colorata look more like R. rotundifolia, while maganeta and variegated seem to be more like macrandra in appearance. The narrow leaf plants are somewhat similar to the thin leaved species we'll be looking at next. Hopefully in the future we will be more aware of what the history and identification of these plants.

Rotala verticillaris

The genus Rotala means wheel and refers to the leaf arrangement in the type species, R. verticillaris. These plants have whorled leaves, meaning three or more leaves or petals radiate from the node.

This beautiful Rotala with long thin leaves is a very dramatic plant, but can be hard to find. R. verticillaris will also do best in an aquarium that has good lighting, supplemental CO2 and fertilizers. I haven't had the opportunity to personally work with this particular species of Rotala yet. Other aquarists have reported that, though it is more difficult to keep than R. rotundifolia, it can be a bit easier than some of the more demanding species, like R. macrandra.

Rotala wallichii

This plant was named after Danish botanist Nathanial Wallich (1786-1854) who studied plants in Indian and other Asian countries while working for the East India Company. R. wallichii is moderately wide spread where it occurs naturally in tropical Southeast Asia.

R. wallichii has lovely needle like leaves, and a very soft look and feel if you run your hand along the leaves. The plant can be grown tall in the back of a tank or kept trimmed toward the front, making little furry bushes. This versatile aquarium plant can sometimes be difficult to locate locally, but can be found regularly for sale through various mail order or web based businesses or auctions.

R. wallichii is another plant that can be difficult to grow unless you have a high tech aquarium. The red tipped leaves can only be achieved with good water quality, lighting, CO2, and other fertilizers. The tank must be free of hair and thread type algae. The fine leaved Rotalas seem to be a magnet for these types of algae, which will grow around the plants.

Rotala hippuris

This is another fine leaved Rotala that's very hard to find in the hobby. R. hippuris, verticillaris, and walllichii are said to have Hippuris syndrome, in reference to the arrangement of their whorled leaves. R. mexicana is another species, rarely seen in the hobby, that can grow in this manner when submerged. Scientists have several ideas for why the leaves grow like this including, reducing self shading, reducing drag in flowing water, and increasing the leafs ability to assimilate CO2.

Like the other fine leaved Rotala, R. hippuris needs optimum conditions to show optimal growth and appearance. Give it good lighting, CO2, fertilizers and keep it free from algae growth.

Two other plants with a similar appearance are being sold as R. vietnam, or R sp. “Vietnam” and R. nanjenshan or R. sp. “nanjenshan.” I can find no reference for these plants in any literature except those concerning aquariums. They may be variations, other species with new names attached to them commercially or less likely, undescribed species.

Rotala ramosior

This plant is a North and South American native. It's often called toothcup, lowland toothcup or lowland rotala. R. ramosior doesn't display the reds so common in many of the other Rotala, which is perhaps why it hasn't been used much in the aquarium, even though it grows wild in most states.

It's found naturally in wet areas, such as areas near lakes or along stream margins. Ramosior means more branched and this plant can have many branches, though the stems are often weak and fallen over. Small pink flowers with 4 petals grow close to the stem.

Check with your local state laws if you consider collecting this plant locally. It is listed as endangered, threatened, rare, or sensitive in 7 states.

The Right Rotala for you

The genus Rotala offers many attractive stemmed plants to the aquarium hobby in a wide range of colors and leaf shapes. Though many require special care, the most commonly found. R. rotundifolia, is quite easy to grow in a variety of conditions, making these a great group of plants for any level of aquarist.


Welcome to the Jungle | Into The Forest | The Creepy Crawlies | A Clearing in the Thicket | Algae Eaters for the Planted Aquarium
North American Natives | Why things go wrong Pt 1 | Why things go wrong Pt 2 (Algae) | Algae Eating Shrimp | Lo-Tech Tanks
Welcome to the Fish Room | The Stemmed Plants | Mosses | A Livebearer Biotope | Planted Tank Social | The Genus Hygrophila | Cyanobacteria
Easy Plants | What I Did Last Summer | Decorations in the Planted Tank | Botany-An Introduction to Plant Biology | Botany-Anatomy of a plant
Botany-How Plants Work | Easy Rosettes | Going High-Tech | Floating Plants | Dealing with Success | Bringing the Outside In | Vallisneria
Hair Algae | Flowering Aquarium Plants Part 1 | Flowering Aquarium Plants Part 2 | Liverworts in the Aquarium | Elements of Design
Planted Aquarium Maintenance | More Mosses | Invaders | Ferns in the Aquarium | Setting up a Planted Aquarium
Seaweeds of the Pacific Northwest | Proserpinaca | Hardware for the Planted Aquarium | Rotala | Neocaridina Shrimp | Lo-tech Tank Tips


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