TankBud

Myriophyllum Guyana

Myriophyllum mattogrossense

Also known as Myriophyllum sp. 'Guyana', Mattogrosso milfoil, Green milfoil, Red foxtail

FreshwaterStemCuttingsSide shoots

Myriophyllum Guyana (Myriophyllum mattogrossense)
TsunamiCarlos · Public domain

Care at a glance

Light
Medium light
CO2
CO₂ beneficial
Temperature
68–82°F
20–28°C
Max height
19.7 in
50 cm
Growth rate
Fast
Placement
Background
Type
Stem
pH
6.0–7.5
Hardness
2–12 dGH
Spread
2.4 in (6 cm)
Nutrient uptake
Root + water column
Growth region
Submersed or emersed
Difficulty
Easy
Family
Haloragaceae
Origin
South America (Mato Grosso region of Brazil)

Overview

Myriophyllum Guyana is a bright green, feathery stem for the background. It is easy, and one of the more forgiving milfoils.

Did you know

Its feathery leaves make Myriophyllum Guyana a favorite spawning mop, both in the wild and in breeding tanks. The dense whorls of fine foliage trap eggs and give fry somewhere to hide. That is partly why milfoils are such popular plants for fish breeders.

Caring for Myriophyllum Guyana

Strip the lower leaves and plant the stems in groups toward the back, one at a time. Myriophyllum Guyana quickly forms a soft, bushy backdrop.

It grows fast even in lower-tech tanks, and medium light keeps it dense. It grows without injected CO2, but CO2 plus regular dosing makes it fuller. An iron-rich substrate or root tabs, plus a liquid fertilizer for the water column, suit it well.

Left alone it reaches the surface, at up to about 20 in (50 cm), so trim and replant the tops. The cut stumps push new side shoots. Keep it at 68 to 82°F (20 to 28°C).

The fine leaves are a magnet for algae when light and nutrients are out of balance. Keep conditions steady and the flow decent.

Good to know

Myriophyllum Guyana belongs to Haloragaceae, the watermilfoil family. The genus name Myriophyllum comes from the Greek for countless leaves, a nod to the finely divided, whorled foliage. The trade name Myriophyllum 'Guyana' is generally applied to Myriophyllum mattogrossense rather than to a botanically distinct plant. It also goes by Mattogrosso milfoil and green milfoil.

In the wild

Myriophyllum mattogrossense comes from South America and is named for the Mato Grosso region of Brazil. It grows in shallow, slow water, forming soft, feathery underwater foliage. It switches between an emersed and a fully submersed form.

Common questions

Does Myriophyllum Guyana need to be planted in the substrate?

Yes. Strip the leaves from the lower part of each stem, then push the stems into the substrate one at a time, a little apart.

Does Myriophyllum Guyana need CO2?

No, but it helps. Myriophyllum Guyana can grow without injected CO2, and added CO2 makes it grow faster.

How much light does Myriophyllum Guyana need?

Myriophyllum Guyana wants medium light. A light sold for planted tanks covers it.

Does Myriophyllum Guyana need root tabs?

They help. Myriophyllum Guyana takes nutrients through both its roots and its leaves. Root tabs near its roots and a liquid fertilizer cover both.

How do you propagate Myriophyllum Guyana?

Myriophyllum Guyana propagates by cuttings and side shoots. Cut off the top of a stem and replant it, and the stump left behind grows new shoots. Cut a side shoot off once it has a few leaves and plant it on its own.

How tall does Myriophyllum Guyana grow?

Myriophyllum Guyana grows to about 19.7 in (50 cm) tall. It grows fast, so expect to trim it often.

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