Monte Carlo (Micranthemum tweediei) Care Guide
Micranthemum tweediei 'Monte Carlo' is a small-leaved carpeting plant from South America, easier to grow than HC Cuba but still benefits from CO2 and strong light.
Overview
Micranthemum tweediei, traded under the cultivar name 'Monte Carlo', is a small creeping plant in the family Linderniaceae. It forms a dense lawn of rounded leaves rarely above 5 cm tall and has become one of the most widely used carpet plants in aquascaping due to its tolerance of moderate light and its faster establishment compared with Hemianthus callitrichoides 'Cuba'.
Taxonomy
- Family: Linderniaceae
- Genus: Micranthemum
- Scientific name: Micranthemum tweediei
- Common cultivar: 'Monte Carlo'
- Trade synonym: New Large Pearl Grass
Habitat
The genus Micranthemum is native to the Americas, ranging from the eastern United States through tropical and subtropical South America. Monte Carlo grows along stream margins and seasonally flooded banks, where it spreads as a creeping mat that can survive both submerged and emersed conditions.
Tank requirements
- Temperature: 20-26 C (68-79 F)
- pH: 6.0-7.5
- GH: 3-10 dGH
- Lighting: medium to high (PAR ~50-80 at substrate)
- CO2: not strictly required but strongly recommended for compact carpet
- Substrate: nutrient-rich aquasoil
- Placement: foreground / carpet
Growth and propagation
Monte Carlo grows at a medium rate. Under CO2 injection and strong light, a carpet typically fills in within about 8 weeks. Propagation is performed by cuttings: trim runners every 10-14 days and replant the trimmings to thicken the lawn. Allowing the carpet to become too thick causes the lower layer to detach from the substrate.
Placement and aquascaping
Monte Carlo is used as a foreground carpet in nature-style and Iwagumi layouts. In low-tech tanks it tends to grow taller and more open; under high light and CO2 the leaves remain small and the lawn is tight. Trimming maintains shape and prevents floating clumps that occur when oxygen bubbles lift the mat.