Ottelia alismoides

Ottelia alismoides is a widespread species found across tropical and subtropical Asia, Africa, and Australia, growing in ponds, rice paddies, and slow rivers. In its submerged form it produces large, broadly oval to heart-shaped leaves that are beautifully translucent, pale to mid-green, and strongly undulate along their margins. The leaves grow on long petioles from a central rosette, creating an architectural, lily-like presence in the midground to background. It is more demanding than Vallisneria or Sagittaria, requiring moderate to bright light and benefiting from CO2 injection, but the visual reward is extraordinary. Water hardness must be controlled — it performs best in soft to moderately hard water.

Light: Medium to high (40–80 PAR); brighter light produces more strongly undulate, compact leaves. CO2: Recommended; supplementation greatly improves growth rate and leaf size. Fertilisation: Regular root tabs every 2–3 months; weekly liquid fertiliser with iron and macronutrients. Placement: Midground to background as a specimen plant; allow 20 cm radius for leaf spread. Propagation: Annual plant in nature; produces seeds or offset rosettes; remove offsets and pot separately.