Tag: bryophyta

Mosses are non-vascular plants and therefore lack true vascular tissues like xylem and phloem. Instead, conduction of water and nutrients is carried out by specialized parenchymatous cells, such as hydroids and leptoids.

The rhizoids are unicellular and unbranched. They anchor the thallus to the substratum and are usually of two types, smooth walled and tuberculated. Rhizoids are present in the mid-rib region of thallus.

Anthoceros is commonly known as a hornwort. Ricciocarpus is a thalloid liverwort, Chara is a green alga known as stonewort, and Lycopodium is a pteridophyte known as club moss.

The plant body  of Riccia is thallus. It is small, green flat and rather fleshy.  It is  gametophytic in nature and hence, haploid.

Riccia plants are small. The plant body is a thallus that is not differentiated into root, stem and leaf. It is strap-shaped and about 0.5 to 4 mm wide and branches dichotomously (equally forked). It is gametophytic in nature.

In bryophytes like mosses and Riccia, the gametophyte is the dominant, independent, and photosynthetic phase of the life cycle. In pteridophytes (ferns), gymnosperms (Cycas), and angiosperms, the sporophyte is the dominant phase.

The antherozoids (male gametes) of mosses are typically spirally coiled, elongated, and possess two flagella (biflagellate) at their anterior end, which help them swim through water to reach the egg.

In Riccia, true elaters are completely absent. Instead, some of the potential spore mother cells do not undergo meiosis and instead degenerate to form sterile nurse cells, which provide nutrition to the developing spores.

In Riccia, the sex organs (antheridia and archegonia) are not exposed on the surface but are deeply embedded singly in chambers on the dorsal surface of the thallus.