Eriocaulon australasicum Southern Pipewort

Eriocaulon australasicum is native to Australia and nearby Pacific regions, growing in the soft, acidic, mineral-poor water of ephemeral pools, sandy lake margins, and seasonal swamps. It forms compact, symmetrical rosettes of narrow to slightly flattened leaves that are shorter and broader than those of E. setaceum, giving the rosette a slightly chunkier, star-shaped appearance that differs attractively from its Asian relatives.

In aquarium cultivation, the requirements are the same demanding profile shared by all Eriocaulon: very soft, acidic water (RO or equivalent), high light, CO2 injection, and minimal macronutrient enrichment. Unlike some of the more commonly available Eriocaulon, E. australasicum remains genuinely rare in the hobby, making it a prized addition for specialists and collectors.

Planted in groups of 5–10 rosettes in fine inert substrate, E. australasicum creates a beautifully varied texture alongside E. cinereum and E. quinquangulare. Its Australian origin also makes it relevant for Australasian biotope aquarium themes.

Light: High; full-spectrum high-intensity lighting for a 10-hour photoperiod; dimmer conditions cause etiolation. CO2: Required; consistent injection at 20–30 mg/l is essential for sustained healthy growth. Fertilisation: Lean, inert substrate with trace elements only; avoid rich soils that disturb the delicate root system. Placement: Foreground in high-tech aquariums; plant individual rosettes 2 cm apart in groups. Propagation: Side rosettes develop at the base of mature plants; detach carefully when 1.5 cm and replant.