Distribution: Aponogeton rigidifolius originates in Sri Lanka.
Appearance: Leaves grow to 24 inches in length and are dark green to brownish. Leaves are somewhat brittle, rough and hard with lightly wavy edges. Forms a rhizome rather than a tubercle so there is no resting period. Flowers are greenish, single-spiked and self-sterile.
Care: This is a rather delicate Aponogeton. It does not transplant well and requires soft water low in salt. Recommended values are 20 ppm to 50ppm carbonate hardness with a pH of 5.5 - 6.5. Temperature should be between 22C and 28C. In unfavourable conditions, leaves become spotty and curl downward. With CO2 fertilization it will tolerate somewhat harder water. Iron fertilizer is appreciated.
Light: 50 watts per 100 liters.
Propagation: Lateral shoots on the rhizome.