Myriophyllum mattogrossense ‘Red’ (Black Pot), commonly sold in tissue-culture or nursery pots.

1. Overview

• Scientific name: Myriophyllum mattogrossense

• Cultivar / trade name: Red

• Pot type: Black pot (nursery-grown, emersed)

• Family: Haloragaceae

• Origin: South America (natural species); red form is a selected cultivar

• Growth type: Stem plant

The “Black pot” designation refers only to the nursery container, not to a different genetic variety.

2. Physical Characteristics

• Leaves:

  • Finely divided, feather-like (whorled)

  • Very delicate texture

  • Turns pink, orange, deep red, or reddish-brown under optimal conditions

• Stem:

  • Soft but upright

  • Can grow tall and bushy with proper trimming

• Height:

  • 20–50 cm (8–20 in), depending on tank depth

• Color intensity:

  • Strongly influenced by light, nutrients, and CO₂

3. Growth Behavior

• Growth rate: Fast (once established)

• Form: Vertical stem growth; branches heavily after trimming

• Adaptability:

  • Grown emersed in pots

  • Will convert to submerged form after planting

Initial melt of emersed leaves is normal during transition.

4. Aquarium Care Requirements

Lighting

• Medium to high light

• High light is required for strong red coloration

CO₂

• Strongly recommended

• Without CO₂, growth becomes weak and color fades

Water Parameters

• Temperature: 20–28 °C (68–82 °F)

• pH: 5.5–7.2

• Hardness: Soft to moderately hard

• Sensitive to unstable conditions

5. Nutrient Requirements

• Heavy feeder

• Requires:

  • Nitrates (NO₃)

  • Phosphates (PO₄)

  • Potassium (K)

  • Iron and trace elements

• Iron is essential for red coloration but must be balanced

6. Planting (Black Pot Preparation)

1. Remove plant from pot

2. Wash off all rock wool thoroughly

3. Separate into small stems (3–5 cm apart)

4. Plant directly into nutrient-rich substrate

Do not plant with rock wool attached.

7. Placement in Aquascape

• Background plant

• Works well in:

  • Dutch-style aquascapes

  • Nature layouts as a red accent

• Best planted in groups for visual impact

8. Trimming & Propagation

• Trim tops when they reach the surface

• Replant healthy cuttings into substrate

• Regular trimming promotes bushy, dense growth

9. Common Problems

• Green growth instead of red: Insufficient light or iron

• Melting after planting: Normal emersed-to-submerged transition

• Leggy stems: Low light or poor nutrient balance

• Algae on leaves: Excess light without nutrient/CO₂ balance

10. Comparison with Similar Plants

11. Why Aquascapers Use It

• Extremely fine texture

• Strong red contrast

• Rapid background fill

• Excellent response to trimming

12. Key Tips for Best Results

• Maintain consistent CO₂

• Use high-quality light (full spectrum)

• Keep nitrates non-zero

• Trim frequently to avoid shading lower stems