Question

Why is the sporophyte of riccia is considered as primitive?

Answer 1

The sporophyte of the bryophytes known as the sporogonium consists of a single and terminal sporangium that has a bulbous foot. It may or may not have an unbranched stalk or the seta.

Riccia is an example of the thallose liverwort genus wherein the sporophyte does not develop a foot. Unlike the complex forms of the sporophyte, the simplest form of the sporophyte like the Riccia genus has the entire zygote taking part in the formation of the capsule wall and the central sporogenous cells.

As it is the simplest form of the sporophyte, Riccia is considered to be primitive.

Answer 2

The sporophyte of Riccia is the most simplest type as the structure is represented only by a capsule without any foot. The sporophyte is entirely embedded within the gametophytic tissue for the nourishment as true jacket with chlorophyllous tissue is absent. Sporogenous tissue is mostly found. Most of the cells of sporogenous tissue become spore mother cells, only a few become sterile which are looked upon as forerunners of elaters. Dehiscence of capsule is absent. The spores simply get free from sporogonium on death and decay of the thallus. This is a long and a simple process. The sporophyte of Riccia lack complexities and therefore is called the simplest among all the bryophytes.