Today we will be talking about one of the most popular foreground plants in the hobby and this is none other than the Glossostigma elatinoides which is commonly known as Glosso.
Glosso is a low, creeping green plant species that are used in aquascaping the foreground of planted aquariums. This species is not ideal for beginners due to its high light, CO2, and nutrient demands. Glosso will thrive and form lush green mats when planted in a nutrient-rich substrate and provided with ample light and nutrients.
Keep reading for more information on Glossostigma elatinoides; this includes its features, habitat, how to plant and care for it in a freshwater aquarium.
Quick Notes about Glosso
| Common Name | Glosso |
| Other Names | Mud mat |
| Scientific Name |
Glossostigma elatinoides |
| Tank Size (minimum) | 10 gallons (~40 liters) |
| Difficulty | Medium to hard |
| Lighting | Medium to high |
| Optimal pH | 6.5 – 7.5 |
| Optimal GH | 2 – 15 |
| Optimal Temperature | 22 – 30 °C (72 – 86°F) |
| Substrate | Needed (nutrient-rich) |
| Growth Rate | Moderate to fast |
| Placement in Tank |
Mostly foreground / midground |
| Height | 3 – 6 cm (1 to 2 inches) |
| Fertilizer |
Recommended |
| CO2 | Recommended |
| Propagation | by producing runners |
Origin of Glosso
Glosso (Glossostigma elatinoides) is a freshwater green plant species, its usage in aquariums dates back to the 1980s. This aquatic plant is known for its versatility and it is commonly used in Nature, Iwagumi, and Dutch style aquascapes for beautifying the foregrounds.
Glossostigma elatinoides can be traced to Glossostigma and this is a genus of flowering plants in the lopseed family Phrymaceae. Glossostigma was previously classified under the family Scrophulariaceae, but after research on phylogenetic relationship, it was revealed that the genus was actually more closely related to Phrymaceae than Scrophulariaceae.
The genus Glossostigma includes six accepted species Glossostigma cleistanthum, Glossostigma diandrum, Glossostigma drummondii, Glossostigma elatinoides, Glossostigma submersum and Glossostigma trichodes. Out of these, Glossostigma elatinoides is the only species renowned for its use in aquascaping.
Habitat of Glosso
Glossostigma elatinoides is a low-growing plant species that is native to Australia, New Zealand, and Tasmania where it grows partially to completely submersed in shallow water, bogs, marshes, and river banks.
Although fairly small in stature, this plant can attain high densities and often form extensive mats on the substrate, hence their common name of Mud mat.
Description of Glosso
Glosso is one of the smallest aquarium plants. It usually grows up to 5 – 6 cm (2 inches) and this makes it a good foreground ground-cover plant.
The leaves of Glosso are bright green in color and tongue-shaped. They are typically small, often measuring 6 mm (0.3 inches) with petioles present (stalks that attach the leaves to the stem).
Notably, the length of its internodes is about 1 cm (0.4 inches), however, this can reach up to 5 cm (2 inches) and it facilitates rapid spread on the substrate.
This plant is a fast grower, having the ability to put out new leaves within a short interval and spreading widely on the aquarium floor.
Also, bubbles of air may appear on the surface of healthy plants especially when there is stable levels of CO2 in the tank water.
The availability of ample lighting, CO2, and nutrients will help the plant attain a low and compact growth form in the aquarium.
Tank Requirements and Water Parameters
Tank size:
The recommended tank size for growing Glossostigma elatinoides is a minimum of 10 gallons (~40 L). Even though this is a small plant it will require stable water parameters and CO2 injections. Unfortunately, it is close to impossible to do in nano tanks.
Water type, Temperature, Hardness, and pH:
Temperature: Optimal temperature for Glosso is between 22 – 30 °C (72 – 86°F). The plant can tolerate slight variations outside the optimal range without issues.
Hardness: Glossostigma elatinoides can thrive in soft to hard water comfortably.
pH: Ideal pH values are considered to be between 6.5 – 7.5. Glosso can withstand slightly acidic water up to the value of 5.0.
Lighting:
This green plant appreciates moderate to high lighting.
Intense lighting allows it to form thick mars on the substrate whereas low light triggers upward growth of the shoots which defies the purpose of cultivating the plant in the first place.
Therefore, for optimal growth, Glosso will need 30 – 50 PAR. In addition, maintain a minimum photoperiod of 8 hours on a daily basis (10 hours preferably).
Read more about it in my article “Advanced Guide to Planted Tank Lighting”.
Substrate:
Glossostigma elatinoides requires a smooth, nutrient-rich substrate to thrive.
Some recommended soil substrates for this plant include (links to check the price on Amazon):
These substrates are rich in nutrients and allow the thin roots of Glosso to penetrate easily.
Read more about it in my article “Top 5 Substrates For Planted Aquariums”.
CO2 and fertilization:
CO2 injection is a necessity as far as Glosso is concerned. One can either use liquid carbon or a pressurized CO2 system to supply adequate doses of CO2 for the plants, some aquarists recommend about 20-30mg/l.
This plant needs stable levels of CO2 to stay healthy and grow densely. So, it’s better to use a pressurized CO2 system.
Additionally, the plants will benefit from regular dosing of root tabs or liquid plant fertilizers rich in macro and micronutrients. This will help to sustain healthy growth and ensure that the plants maintain the best coloration.
Important: If you keep shrimp in the tank with Glosso, 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 Glosso
Glosso is a demanding plant and it is not ideal for beginners since it requires a great deal of maintenance and nutrient supplementation to keep the carpet in excellent condition.
The carpet should be frequently trimmed in order to maintain a low, compact look which is usually about 1 inch (3 cm). If you don’t trim the plants from time to time, the old foliage will rot as new ones tend to smother them as they grow. Also, by trimming it low, it will encourage lateral growth.
In the same vein, never allow the carpet to get lengthy as that would ruin the carpeting effect.
Also, do not forget to cut off yellow leaves and decaying shoots to make way for the growth of new foliage. Collect all the clippings with a sieve or fishnet for proper disposal, stir the carpet briefly to allow dirt particles to rise up to the surface, then carry out a partial water change to eliminate nitrates as well as impurities suspended in the water column.
It is necessary to ensure the availability of high lighting for proper horizontal growth of the shoots, low light will result in leggy growth and that should be avoided at all costs.
Furthermore, make sure to use root tabs or dose liquid fertilizers, etc. to provide essential nutrients needed by the plants.
I repeat, do not underestimate the importance of high light and CO2 injection. If you try it in low light with no CO2 setup, Glosso would either grow vertical and very slowly or die out pretty fast.
Remember, you are aiming for a beautiful green carpet, so it’s in your best interest to supply the plants with vital nutrients to keep them healthy and vivid.
Planting and Propagation Glosso
Here, you are required to cultivate Glossostigma elatinoides in a distinct pattern in order to achieve a nice carpet effect.
The plant comes potted, so you have to remove the binding material, and quarantine/disinfect the bunch if needed.
Note: For example, there is no need to do that if these are “in vitro” plants, it means that they are cultivated on nutrient media under sterile, laboratory conditions.
Next is to prepare the plants for planting.
- Split the clumps of Glosso into small portions of individual plantlets. In most cases, every pot can be divided into 10 – 15 portions.
- Afterward, spread the trimmed plantlets on a tray, mist them with aquarium water or cover them with a damp paper towel to keep them moist, thereby preventing them from drying out.
Now, you can proceed to split the clump into small portions for planting. Because of their small size, I have to warn you that planting Glosso is not fun at all!
The individual plants should be placed into the substrate using a pair of tweezers (link to check the price on Amazon), make sure to bury the plantlets down into the substrate so that just the leaves are showing. It will prevent them from floating afterwards.
While planting, maintain a spacing of 2.5 cm (1 inch) apart from each other to allow the runners to spread properly.
Best results are attained when the plantlets are cultivated in a chessboard or grid-like pattern as it encourages coverage and formation of dense vegetation underwater.
Be sure that the new plants are not shaded by other plants in the tank or by aquarium decor, they need enough light to bloom.
Glosso propagates rapidly by sending off runners or lateral shoots which start forming once the plants mature in the aquarium.
Alternative Way of Growing Glosso
Another way to plant and grow Glossostigma elatinoides is to use the Dry Start Method (read more about it). By the way, this method also shows that this plant a great choice for paludarium setups.
The Dry Start Method still significantly boosts the development of the slow-growing plants, cycles the substrate, and removes any algae problems!
Problems Associated with Glosso
Melting: Glosso starts to die out after planting. Actually, this is not a rare problem with plants that were not grown underwater in their earliest stages. A transition from an emersed form to a submersed form will prompt a melt and the plant will take some time to bounce back to life by growing new leaves and modifying its structures to adapt to the new environment.
Leggy growth: As discussed in the earlier sections, growing Glosso in low light conditions will prompt leggy growth— a situation whereby the stems are very long and thin, therefore you need to provide intense lighting for best growth.
Leaf rot: As the plant grows and forms new leaves; these leaves will smother old ones causing them to rot from underneath. Due to this reason, it is recommended to trim the Glosso carpet frequently.
Yellowing of leaves: This problem can either be due to inadequate lighting or nutrients to encourage healthy growth.
So, make sure to utilize a nutrient-rich substrate in your planted tank, dose liquid fertilizers especially those rich in Nitrogen, Phosphorus, Potassium, Magnesium, Boron, Manganese, and chelated Iron. Lastly, ensure that the plants receive intense lighting at least 8 hours daily.
You can also read “How to Spot Nutrient Deficiencies in Aquatic Plants”.
Glosso and Compatible Tankmates
This ground-cover plant is suited for planted tanks housing mostly docile freshwater fish and a variety of small invertebrates. The Glosso carpet provides a large surface area for bottom-dwelling fish and inverts to roam and maneuver in search of tiny food bits or particulate matter to ingest.
Fish:
The plant is best kept with small, peaceful community fish such as Bleeding heart Tetra, Neon tetras, Mollies, Killifish, Swordtails, White Mountain Minnows, Zebra Danio, Cherry Barb, Sunburst Platy, Endlers, Mollies, Otocinclus Catfish, Pygmy Cory Catfish,
Shrimp:
Inverts are not left out. Considering the fact that Glossostigma elatinoides can tolerate a wide range of pH, it is possible to keep it with any dwarf shrimp species.
Freshwater snails:
Once again, ornamental snails should not be kept in a tank with low PH for a long time. It will negatively affect their shell. However, if your pH is close to 7.0, it is possible to keep almost any snail or dwarf shrimp you like. For example, Japanese trapdoor snails, Ramshorn snails, Nerite snails, Malaysian Trumpet snails, Black Devil Snails, Asolene spixi, Rabbit Snails, etc.).
Avoid or Be Careful
However avoid fish species that may find the plant too palatable, e.g. like Silver dollars, Bueno Aires tetras, Koi fish, Goldfish, Oscars, Rainbow, Jack Dempsey, Clown loaches, African Cichlids. These species can really cause problems in the planted tanks.
Glosso and most types of crayfish or freshwater crabs are not a good combination as well. These animals will cut, eat, and uproot everything in the tank. So, keep it in mind.
Buying Glosso
Being a popular aquarium plant, Glosso is readily available for purchase in local fish stores, and it costs about $10 for a decent-sized clump.
If you want to decorate the forefront of a nano tank with this plant, then a clump should be enough, however, you will need more for a large tank.
Be sure to obtain healthy plants as they stand a better chance of thriving in your tank; avoid specimens with yellow or brown leaves, rips, curls, and spots.
You should bear in mind that fake Glosso seeds exist. Actually, the online markets have been flooded by knock-off Glosso seeds.
Do not trust any carpeting seeds sold online unless they are from reputable sellers! Those seeds are generally some sort of Hygrophila (which can be illegal in some parts of the US) and do not stay small, or just terrestrial plants (which will die after a few weeks underwater).
Quarantine Glosso
Do not forget to quarantine Glosso before putting it into your aquarium if necessary!
- The plant can have parasites, pests like snails, or even predators (dragonfly, damsefly nymphs, etc.).
- It could also be treated with chemicals (pesticide) to remove parasites, snails, etc. However, these chemicals are extremely poisonous to fish, shrimp, and other invertebrates.
To find out more, read my articles:
How to Remove Snails from a Shrimp Tank.
How to Quarantine and Disinfect Aquarium Plants.
Pesticides in Shrimp Tanks. Plants Quarantine.
In Conclusion
There are lots of plants in the aquascaping world, each with its strengths and weaknesses. Glosso may not be the best pick in the carpeting category but it does a terrific job at establishing dense vegetation on the forefront of planted tanks.
Cultivate Glosso in the right manner, give it appropriate care and attention, and you will be rewarded with an attractive, healthy green carpet that will take your aquarium’s aesthetics to a whole new level.
Anyway, if you won’t be able to devote time and energy to cater for this demanding plant, you can opt for easy alternatives like Marsilea hirsuta, Monte Carlo, or Dwarf Sagittaria that require minimum upkeep.