Myriophyllum sp. 'Guyana'

Myriophyllum sp. 'Guyana' is a collector form from Guyana not yet assigned a formal species name, distinguished by unusually dense, tightly packed whorls of bright emerald-green leaves that create a more solid, carpet-like column compared to the open, airy appearance of M. mattogrossense. Under strong lighting the foliage has an almost jewel-like intensity.

It is moderately demanding, requiring high light and CO2 injection for the characteristic dense whorl formation. Without CO2 the internodes elongate and the whorls become sparse. It prefers soft to moderately soft water and slightly acidic to neutral pH.

An excellent choice for aquascapers who want the textural quality of a milfoil but with more visual density and depth. Best used in the background of medium to large planted tanks as a rich green foil to coloured stem groups.

Light: High (60–90 PAR); dense emerald-green whorl formation requires strong light. CO2: Required at 20–30 mg/L; sparse whorls develop without adequate CO2. Fertilisation: Regular micro and macro dosing; potassium and iron maintain vivid green colour. Placement: Background; groups of 7–11 stems with 2–3 cm spacing. Propagation: Trim tops at 12–15 cm and replant; roots develop within 3–5 days.