Topapana or Water lettuce (Pistia stratiotes, family: Araceae) is a free floating round-shaped aquatic plant, attaining a length of 10-15 cm. Its submerged roots remain in clusters. The perennial plant looks like Rose or Cabbage.
Other Bangla name: Tokapana, Pana, Golap-pana, Boro hodi, Bara-pana.
The stemless small plant is found everywhere in shallow water or in the mud of ditches in Bangladesh. Sometimes they are seen floating in the large colonies. It is also found in Indian subcontinent and Southeast Asia.
Leaves are pale green or yellowish, 4-10 cm long, leaf apex rounded with soft hairs. Occasionally their leaves turn yellow; probably due to lack of nutrients from the soil. This can happen by lacking the water also.
Flowers in spathe, from the center of the leaves. They are yellowish green. Fruit is berry, few seeded.
It blooms in summer. It is propagated by stolon and seeds.