Tag: pictorial feature of plant kingdom

Riccia, being a liverwort, possesses unicellular, unbranched rhizoids. These rhizoids are of two distinct morphological types: smooth-walled and tuberculate.

In liverworts, spores germinate directly to form the flat, thalloid gametophyte without forming an intermediate stage. In contrast, moss spores germinate to form a filamentous juvenile stage called a protonema.

The word bryophyte is the collective term for mosses, hornworts and liverworts and bryology is the study of bryophytes. Bryophytes derived from Greek, 'Bryon' means moss and 'phyte' means plant. 

Pteris (a pteridophyte), Anthoceros (a hornwort), and Funaria (a moss) all produce motile, flagellated male gametes (antherozoids) that require water for fertilization. Other groups like angiosperms (Hydrilla, Calotropis) produce non-flagellated male gametes.

The sporophyte of Riccia is extremely simple, consisting only of a capsule embedded within the gametophytic thallus. Lacking any photosynthetic tissue, foot, or seta to absorb nutrients independently, it is completely dependent on the gametophyte, making it a total parasite.

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.