Glossostigma elatinoides
The original aquascaping carpet, popularised by Takashi Amano. Tiny paddle-shaped leaves form a dense bright-green mat. Sister species to HC Cuba but slightly larger leaves and a touch more forgiving. CO₂ is non-negotiable; needs high light to stay flat, under-lit Glosso grows vertically.
Glossostigma (Glossostigma elatinoides) is a carpet / stem aquatic plant for the foreground of a planted tank. It reaches 1–3 cm under good conditions and grows at a fast rate. Light: high. CO₂: required. Target 20–26 °C, pH 5.5–7.0, and 1–10 dGH. Substrate: Fine, active nutrient-rich substrate (ADA Amazonia or similar). Propagate via cuttings / runners spread horizontally.
Care at a glance
The original aquascaping carpet, popularised by Takashi Amano. Tiny paddle-shaped leaves form a dense bright-green mat. Sister species to HC Cuba but slightly larger leaves and a touch more forgiving. CO₂ is non-negotiable; needs high light to stay flat, under-lit Glosso grows vertically.
By Mike ElmiraUpdated 2 min read
Part of our complete guide to the planted aquarium.
The parameters that decide whether glossostigma fits in your tank.
Phrymaceae
Carpet / Stem
Foreground
Fine, active nutrient-rich substrate (ADA Amazonia or similar)
Cuttings / runners spread horizontally
Damp lake margins of New Zealand and Tasmania
New Zealand, southeastern Australia
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Hard-won lessons from the tank.
The original 'aquascaping carpet' that Takashi Amano popularised in Nature Aquarium World. Dry-start method is the most reliable path — plant tiny clumps 2 cm apart on damp substrate, cover with film, mist daily, 8-hour light cycle. In 4–6 weeks you have a 90%+ complete carpet that transitions to submerged form when flooded. Slightly more forgiving than HC Cuba but still demands CO₂ and high light.
What can go wrong and how to spot it.
Failure modes, in order of how dramatic the fix is.
Tall vertical growth: insufficient light (this is the most common Glosso failure). Pale/yellowing: nitrogen + iron. Lifting carpets: substrate decay or CO₂ instability.
Hair algae loves Glosso just like HC Cuba. Stable CO₂, dialled-in lighting (60+ PAR at substrate but with 4–5 hour photoperiod during establishment), and good water flow prevent it.
The practical routine, read top to bottom.
Heavy CO₂ user; stable CO₂ at 30 ppm is non-negotiable. Active nutrient substrate (ADA Amazonia, UNS Controsoil, Tropica Aquarium Soil). Iron and macro EI-style dosing.
Trim with sharp curved scissors every 2–3 weeks once carpet establishes. Aggressive horizontal pruning forces runner spread. Vacuum trimmings immediately — floating fragments root randomly and produce messy patches.
Where it comes from, how it behaves, and the variants you'll see at retail.
Where it lived before it came home.
Wet meadows, lake shores, and shallow pools across New Zealand and southeastern Australia. Naturally grows partially emersed in muddy soil; the fully submerged form is largely an aquarium adaptation.
Vigorous emersed grower with slightly thicker oval leaves. Almost all wholesale arrives emersed via tissue culture; transitions to submerged within 2–3 weeks via dry-start or controlled flooding.
Small white flowers emersed; never flowers submerged.
The named cultivars and the lookalikes worth flagging.
Only one form is sold in the hobby — G. elatinoides. Sometimes confused with G. diandrum (a slightly different species rarely available).
Often confused with HC Cuba — Glosso leaves are larger oval-paddle-shaped at 5–8 mm vs HC's 2–3 mm round. Marsilea hirsuta in clover-form is occasionally mislabelled.
Direct answers to the questions search engines and AI assistants surface most often about this species.
CO₂ requirement: required. Light requirement: high. Under stable injected CO₂ the plant grows at a fast rate.
Glossostigma (Glossostigma elatinoides) needs high light. Run a photoperiod of 6–8 hours; longer photoperiods invite algae unless CO₂ and dosing are dialled in.
Position: foreground. Substrate: Fine, active nutrient-rich substrate (ADA Amazonia or similar) It typically reaches 1–3 cm.
Propagation method: Cuttings / runners spread horizontally. Glossostigma is a carpet / stem plant.
Target 20–26 °C, pH 5.5–7.0, and 1–10 dGH. Flow tolerance: low to medium.
Difficulty: 4/5. Advanced, demands dialled-in CO₂/dosing or precise water chemistry.
A planted tank is a system. Pair this plant with one entry from each other pillar to plan the whole scape.
