Microsorum sp. 'Borneo'

Microsorum sp. 'Borneo' is an undescribed or informally classified Microsorum species collected from the island of Borneo, where it grows submerged or emergent along forest streams and river margins. It produces bold, somewhat undulating fronds with a deep, rich-green colour and prominent venation that gives it a more rugged appearance than the standard Java fern. Fronds typically reach 25–35 cm, making it a substantial midground to background plant.

This species is less commonly available than Java fern cultivars but is increasingly sought after by specialist aquascapers and biotope enthusiasts. Its care is broadly similar to other Microsorum — attach to hardscape, provide low-to-medium light and stable water quality. It is somewhat less tolerant of hard water than the standard Java fern and performs best in soft to moderately hard conditions. CO2 supplementation significantly improves growth and frond quality in this species.

Light: Low to medium; best growth occurs under moderate indirect light from LED or T5 fixtures. CO2: Recommended for best results; noticeably improves frond size, colour, and growth rate. Fertilisation: Bi-weekly liquid micronutrients; soft water tanks benefit from additional potassium and trace elements. Placement: Attach rhizome to driftwood or smooth rocks in midground to background positions in the aquarium. Propagation: Divide rhizome into sections with 2–3 fronds; re-attach to new hardscape with thread or cyanoacrylate gel.