Kopi-pana or Kariba weed, Salvinia molesta
Kopi-pana or Kariba weed (Salvinia molesta, family: Salviniaceae) is a completely free-floating fern with whriled leaves, attaining a length of 30 cm. Its submerged brown-colored leaves look a lot like roots. It usually prefers to live in large colonies in stagnant water. Its original home is Brazil. The species is now well adapted to the tropics of the world. The perennial aquatic herb has been considered as an invasive plant in many countries.
Other names: Aquarium watermoss, Water velvet, Giant azolla, Giant salvinia, African pyle, Australian azolla.
Its stem is located horizontally under the water and three whorled fronds (leaves) emerge from each node of that. Fronds are light green or yellowish green, oblong-obovate, 2.5-5 cm long, opposite. The sumerged one is about 25 cm long, looking like roots.
The plant is a fern, so it does not produce flowers or fruits. So it has to take another process to propagate. Egg-shaped sporocarps, developed in elongated chains among the submerged leaves produces numerous microscopic sporangia. They can quickly double their numbers in just 2 to 10 days by this process. Due to this, they spread the surface of the waterbodies very quickly and this causes damage to other aquatic plants and animals.
The aquatic plant quite is beautiful. it can be planted as ornamental plant in your aquariums.
Synonyms: Salvinia auriculata, Salvinia adnata.