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.