Aquarium plant · carpeting

Micro sword

Lilaeopsis brasiliensis

Also known asBrazilian micro sword · Grasswort · Lilaeopsis novae-zelandiae (related species)

intermediate slow grower high light no CO2 needed goldfish-proof
Max height
7 cm
Growth rate
Slow
Lighting
High
Difficulty
Intermediate

Water parameters

Temperature
1520253035
1828°C
pH
45.578.5
6.0–7.5
Hardness
0102030
2–18 dGH
·Tolerates brackish
Tolerates cold (unheated)

Light and nutrients

high light
CO2 not required
CO2 boosts growth and color
root feeder

Substrate type: nutrient preferred. Propagation: runners.

Foreground Midground Background

Substrate compatibility

SubstratepH effectNutrient load
Aquasoil (ADA Amazonia) lowers pH very high
Mineralized clay substrate (Seachem Fluorite) neutral / inert moderate
Dirted tank (mineralized topsoil) (DIY soil substrate) slightly acidic very high
Inert sand (Pool filter sand) neutral / inert none

With fish

Safe with plant-eaters
May get uprooted
Tolerates root disturbance

Origin and habitat

A small grass-like aquatic of the carrot family, Apiaceae, Lilaeopsis brasiliensis, the Brazilian micro sword or grasswort, native to southeastern South America from Brazil through Paraguay to Argentina, in marshes, river margins and shallow water. It makes rosettes of narrow, flat, bright-green leaves 38 cm tall and only 23 mm wide from a creeping stolon, spreading along the substrate to bud new rosettes and, in time, a grassy carpet. In the trade it is a foreground carpet, though less popular than dwarf hairgrass or HC because it fills in more slowly and openly, giving a natural-meadow look rather than a manicured lawn. The genus holds several look-alike species, including L. mauritiana and L. novae-zelandiae, and L. minor is often treated as synonymous with brasiliensis; all share the same stoloniferous habit.

Care notes

Moderate care, and really a high-tech carpet at its best. It needs strong light, two to three watts per gallon or the LED equivalent, for a dense carpet, and CO2 makes a big difference; in a low-tech tank it grows slowly if at all, leaving a sparse, open mat that takes many months, while with CO2 and bright light it knits together in six to ten weeks. It is a root feeder, so plant small tissue-culture portions a couple of centimetres apart in a nutrient-rich substrate, and use root tabs. It stays shorter, 35 cm, under strong light and a touch taller in moderate light. It spreads on its own by stolons that root new plantlets, which can be cut and replanted. It grows best warm, in the low-to-mid 20s Celsius, but tolerates cooler water better than most tropical carpets, which makes it usable in unheated temperate tanks. Trim the top to control height. Digging fish can tear up the shallow stolon network, so avoid earth-moving cichlids and geophagus. It is an ornamental carpet, not a crop, so it is unsuited to media-bed aquaponics or hydroponics.

Further reading