XVI International Botanical Congess

The family Podostemaceae comprises of 46 genera and 260 species distributed in the tropical and subtropical regions of the world.Podestemads grow attached to rocks and boulders by means of rhizoids and haptera in gushing rivers and waterfalls.The plant body is generally thalloid and polymorphic.The thallus bears short vegetative shoots on the dorsal margin which are replaced by floral shoots during the reproductive phase. Whether the thallus is of shoot or root origin has been a subject of much discussion.The paper communicates my findings on the origin,development and nature of thallus in Indian Podostemads.The structural complexity of the thallus, the origin and nature of the vegetative and reproductive shoots have been examined.The information is discussed in light of existing literature.The possible adaptive and evolutionary significance of the thallus will be highlighted.