Aquatic PlantsBeginner🌤️ Bright indirect

Monte Carlo

Micranthemum tweediei · also called Micranthemum tweediei 'Monte Carlo', Tweedie's pearlweed, Monte Carlo Micranthemum, New Large Pearl Grass

🐾 Pet-safe

Generally non-toxic to cats and dogs.

A versatile carpeting plant with small round leaves that forms a fresh green foreground lawn. More forgiving and low-tech-friendly than dwarf baby tears, making it a popular beginner carpet.

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	Linderniaceae
Native origin	South America (northern Argentina, Uruguay, southern Brazil)
Care difficulty	Beginner
Light	Bright indirect
Pet toxicity	Pet-safe

Light

Medium-to-high light (around 30-60 PAR at substrate). Carpets well even under moderate light, but higher light produces a tighter, lower mat. Under dim light it grows leggy and reaches upward instead of creeping. The 'bright_indirect' value here stands in for medium-to-high aquarium light.

Water

Temperature 20-26 C, pH 6.0-7.5, soft to moderately hard water (roughly 1-15 dGH). Appreciates a balanced water-column fertiliser; iron-rich dosing keeps the foliage a vivid green.

Soil & potting

Best rooted in a nutrient-rich aquasoil for a fast, lush carpet; it will also creep over and root onto hardscape (wood and rock). Plant small portions pressed into the substrate. Root tabs help in inert substrates. Stems readily put down roots wherever they touch. It is a substrate/hardscape-rooting carpeter, not a rhizome epiphyte, so portions can be safely planted into the substrate.

Environment — humidity, temperature, placement

CO2 is not mandatory but highly beneficial for a dense, fast carpet; it is one of the more reliable non-CO2 carpeting options. Gentle-to-moderate flow. Foreground-to-midground placement, and can also be draped over hardscape. Grows easily emersed (most tissue culture/pots are emersed) and converts to submersed form.

Propagation

Spreads via creeping horizontal stems that root as they go. Propagate by trimming runners/stem sections and replanting them, or by dividing a mat. Regular trimming keeps the carpet low and encourages lateral density.

Toxicity detail

Non-toxic and shrimp/fish safe; widely used in shrimp tanks. Not listed as invasive or regulated, but as with all aquarium plants, do not release into local waterways; dispose of trimmings in the trash.

Growth stages

How this plant changes through its life — each stage often has its own care, diet and space needs.

Photo coming soon

Spore / recruit

Aquatic plants and macroalgae establish from spores, seeds, or drifting fragments that settle and attach to substrate or rock. Many freshwater aquarium plants and marine macroalgae also spread readily from a detached piece that takes root or holdfast.

Photo coming soon

Young growth

Young growth puts out its first blades, fronds, or leaves and anchors with roots or a holdfast. Submersed plants may look different from their emersed form, and growth speeds up as the plant adapts to the water's light and nutrients.

Mature

A mature aquatic plant or macroalga reaches its full size and characteristic shape, forming the dense growth, runners, or fronds typical of the species. Established plants spread to fill space and can be divided or trimmed to propagate.

Sources

Tropica - Micranthemum 'Monte Carlo' plant database (care guide)
Wikipedia - Micranthemum (encyclopedia)