Aponogeton madagascariensis Seeds

Looking down into a large aquatic tank with a pot of Aponogeton madagascariensis.

 Aponogeton madagascariensis, the Madagascar Lace Plant, is a submerged aquatic with naturally occurring holes in its leaf blades. The leaves are like window screen, with a network of veins and photosynthetic tissue, but with gaps in the leaf between the veins. Aquatic plants have more difficulty than terrestrial plants obtaining carbon dioxide, because gas diffusion is much slower in water than in air; the lacy leaves of A. madagascariensis probably are an adaptation to create more surface area for gas exchange.

Aponogeton madagascariensis inflorescence, late summer.

As is the case with many aquatic plants, A. madagacariensis sends its flowers above water for pollination. The flowers seem to be able to self-pollinate and if conditions are right give rise to clusters of small, green, horn-shaped fruits a few weeks later.

Aponogeton madagascariensis fruiting shoot shedding floating seeds.

When ripe, the fruits split open and release seeds. The seeds are a milky violet color and have a water-repelling waxy surface, enabling them to float and disperse away from their parent plant. After floating for a day or two, the seed coat becomes clear and water-logged, and splits open to release the green embryo inside, which sinks to the bottom. I've been gathering the seeds and putting them in submerged pots of sand and soil, and hope to get some germination and Lace Plant seedlings soon.