Micro sword: the grassy carpet
Lilaeopsis brasiliensis
A short, lawn-like grassy carpet that spreads by runners.
Where it comes from
Lilaeopsis brasiliensis is a small marsh plant from South America. Despite looking exactly like a fine grass, it is actually a member of the carrot family, spreading across wet ground by underground runners.
What to expect
It produces tufts of narrow, flat blades a few centimetres tall that knit together into a neat, bright lawn. It reads as a true grass carpet — a different texture from the leafy Monte Carlo or clover-like Marsilea.
How to keep it
Micro sword is not difficult, but it is slow, and it needs good light to stay short and carpet properly — in low light it grows taller and thinner and never really fills in. CO2 is not essential but makes establishment far faster and the lawn denser. A nutrient-rich substrate is its biggest ally.
| Parameter | Value |
|---|---|
| Lighting | Medium to high — tall and sparse in low light |
| CO2 | Not required; strongly beneficial |
| Temperature | 18–26 °C |
| pH | 6.0–7.5 |
| Hardness | Soft to hard |
| Fertiliser | Rich substrate; root tabs |
| Substrate | Nutrient-rich |
| Growth rate | Slow to moderate |
| Placement | Foreground |
| Difficulty | Medium |
How to carpet it
Split the pot into small plugs and plant them a couple of centimetres apart; the runners spread outward and join up over time. Trimming the top with scissors encourages it to thicken rather than lengthen.
What goes wrong
Slow establishment and tall, sparse growth are the two frustrations, both usually down to weak light or a lean substrate. Algae can also settle on the slow blades early on — keep flow and cleanliness up while it establishes.
More plants in this series
- Dwarf hairgrass — the finer grassy carpet
- Monte Carlo (Micranthemum tweediei) — the leafy bright carpet
- Dwarf sagittaria (Sagittaria subulata) — the taller grassy runner