Aquatic PlantsBeginner🌗 Medium light
Water lettuce
Pistia stratiotes · also called Nile cabbage, Water cabbage, Shellflower
Can cause mild irritation or GI upset if chewed.
Water lettuce is a floating plant that forms rosettes of soft, ribbed, velvety leaves resembling a head of lettuce, trailing long feathery roots that offer superb cover and a spawning/fry refuge. It is a powerful nutrient exporter but grows large and is a regulated noxious weed in many regions.
Educational only. KinStation content is reviewed by licensed veterinarians but cannot replace an in-person exam. Always consult a licensed veterinarian or board-certified specialist for diagnosis, treatment, or any decision affecting your pet's health.
Quick facts
| Category | Aquatic Plants |
| Family | Araceae |
| Native origin | Pantropical; likely native to Africa/South America, now widespread in tropical and subtropical regions worldwide |
| Care difficulty | Beginner |
| Light | Medium light |
| Pet toxicity | Mildly toxic |
Light
Does best under medium to high light; stronger light keeps rosettes compact and healthy, while too little light causes small, pale, leggy growth. As a surface floater it intercepts light directly. Very intense light combined with low humidity can scorch leaf tips.
Water
Temp 22-30 C (72-86 F) preferred (a warm-water tropical plant), pH 6.5-7.5, soft to moderately hard. Heavy feeder that removes nitrate and phosphate from the water column; benefits from iron and trace-element dosing if leaves yellow. Prefers warm, stable, nutrient-rich water. No CO2 injection required.
Soil & potting
Not an epiphyte and not rooted in substrate - no substrate needed; the long trailing roots absorb nutrients straight from the water and serve as a biological filter and fry shelter. Do not plant or bury it; let it float freely.
Environment — humidity, temperature, placement
No CO2 required (atmospheric CO2). Needs calm surface water and dislikes water droplets on its fuzzy leaves, which cause rot - keep surface agitation gentle and avoid spray bars or skimmers hitting it. It often grows partly emersed and appreciates humid air above the water (a lid raises humidity but trapped heat/condensation can also rot it, so allow some airflow). Floating plant only; can grow quite large.
Propagation
Spreads vigorously via stolons (runners) that bud off daughter rosettes, much like a strawberry plant; separate the offsets once rooted. It can also flower and produce seed. Thin frequently to prevent it overtaking the surface.
Toxicity detail
Mildly irritating - leaves contain calcium oxalate crystals that can cause irritation if ingested by pets or humans, so it is considered mildly toxic to mammals; it is generally safe in the aquarium for fish and shrimp. Critically, Pistia stratiotes is a state-listed noxious/invasive weed in many areas - it is prohibited or restricted in numerous US states (e.g. Florida, Texas, Louisiana, California, South Carolina and others) and regulated in parts of Australia. Check local regulations before buying, and never release it into natural waterways - dispose in the trash.
Growth stages
How this plant changes through its life — each stage often has its own care, diet and space needs.