What is Riccia thallus?

What is Riccia thallus?

Riccia is a genus of liverworts in the order Marchantiales. These plants are small and thalloid, that is not differentiated into root, stem and leaf. The thallus is dorsiventrally differentiated. Its upper (dorsal) surface is green and chlorophyll-bearing, with a mid-dorsal longitudinal sulcus (furrow or groove).

Is present on the dorsal surface of the thallus of Riccia?

A median longitudinal furrow or depression is present on the dorsal surface (Fig. 153).

What is the shape of Riccia?

Pear-shaped.

What branching is Riccia thallus?

The thallus in Riccia is dichotomously branched and the growing point is situated in its apical notch.

What is the habitat of Riccia thallus?

3.1 Distribution and Habitat Most of the species of Riccia are terrestrial while few are aquatic in nature. The terrestrial species grow on clayed damp soil or tree trunks or wet walls while aquatic species occurs as free floating or submerged in pools, ponds or lakes.

Which structure causes apical growth in Riccia?

A row of 3-5 apical cells.

What is Riccia sporophyte?

The riccia sporophyte consists of a peripheral layer of cells that form the wall of the capsule and a central mass of the mother cell that contains spores. The diploid zygote is the first generation of sporophyte cells. The upper cell is called the epibasal cell, and the lower cell is called the parabasal cell.

Is Riccia an amphibian?

Some bryophytes are aquatic, like-Riccia fluitans, R. abuensis, Ricciocarpus natans, Riella. Some species of Sphagnum and Fontinalis.

What is male reproductive structure in Riccia?

The sex organs in bryophytes (Riccia, Funaria), are multicellular and jacketed. The jacket of sterile cell around the sperm and egg is an adaptation to a life on land. The male reproductive organs are antheridia and female reproductive organs are archegonia.

Why do sporophyte of Riccia is considered as primitive?

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.

Why Riccia is an amphibian of the plant kingdom?

Explanation: Riccia and Funaria are non-vascular plants which are found on land. They require water for survival and reproduction. They are also known as the amphibians of Kingdom Plantae.