Q.Collect the information about the viviparous germination in plants growing along seashore.

Viviparous germination is the germination of a seed while the fruit is still attached to the parent plant; it is characteristic of mangroves of the seashore such as Rhizophora, Sonneratia, Avicennia and Bruguiera, whose seedlings drop into the mud already rooted-ready. …

Points to collect for the report.

1. What it is - in vivipary the seed has no dormancy; the embryo grows continuously inside the fruit while it hangs on the parent. The radicle and hypocotyl elongate into a long, heavy, green, spindle-shaped structure that projects out of the fruit.
2. Where it occurs - in mangrove plants of salt marshes and tidal seashores, e.g. Rhizophora, Bruguiera, Ceriops, Sonneratia, Avicennia and Aegiceras (India has such forests in the Sundarbans, along the Konkan and Gujarat coasts, and in the Andaman and Nicobar islands).
3. How it helps - the soil is water-logged, oxygen-poor, salty and washed by tides, so a seed dropped there would be carried away or would rot. The pre-grown seedling is heavy and pointed: when it separates it falls vertically, pierces the soft mud and is anchored within hours by lateral roots, before the next tide arrives. If it falls into water it floats upright and roots wherever it is stranded. …