Riccia is a genus of liverworts in the order Marchantiales. These plants are small and thallose, that is not differentiated into root, stem and leaf. Depending on. Riccia is a thallose liverwort in which the vegetative plant, which is a gametophyte, generally forms rosettes due to the crowded growth of the thallus lobes this. Riccia description with images for under graduate students. the gametophytic phase of the life cycle ends with the formation of zygote.

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Spores are very small 0. Antheridium is present singly in an antheridial chamber.
Six jacket initials divide transversely into cycld neck initials tier and lifee venter initial tier Fig. Transition onto Land Advantages of living in the lige included… 1. In India a in polyploid species gaugetica Udar and Chopra reported 24 n and 48 In chromosomes number. One of the antherozoids penetrates the egg and fertilization is effected Fig. These cells are called jacket initials. Antheridial chamber, in which an antheridium lies, communicates with the clorsal surface of the thallus by terminal opening.
These cells contain chloroplast and are capable of developing into new thallus. The vegetative plant or thallus in Riccia, is a gametophyte, whose cells are haploid. When a spore falls on a suitable place, it germinates by the production of a long tube. This is a question and answer forum for students, teachers and general visitors for exchanging cycl, answers and notes.
Fertilization takes place in the presence of water the antherozoids liberated in the surrounding water swim towards the archegonia, being attracted chemotactically by the mucilage coming out of the archegonia. Pife species the assimilatory region is spongy being formed of irregularly placed air spaces which are separated from each other by single layered partitions whose cells are rich in chloroplasts.
These plants are small and thallosethat is not differentiated into root, stem and leaf. Vegetative reproduction in Riccia is quite common and takes place by the following methods: Simultaneously the nucleus also becomes crescent shaped, homogeneous and ultimately comes in contact with the blepharoplast.
By using this site, you agree to the Terms of Use and Privacy Policy. Each archegonium is a flask-shaped structure having a multi-cellular stalk.
Riccia – Wikipedia
It lies near the periphery of the protoplast Fig. Primary venter cell divides only once and forms a small venter canal cell and a large egg Fig. California it is 9 Siler, In the upper two cells of the row two vertical divisions take place at right angle to each other producing a group of eight ceils or octants.
The price of the …. The male sex organ is the antheridium while the female sex organ is the archegonium Sex organs develop in acropetal succession, ie. In smooth-walled rhizoids both the inner and outer wall layers are fully stretched while in tuberculated rhizoids the inner wall layer modifies cyclee peg-like or plate-like in growth which projects into the cell lumen Fig.
The basal swollen portion of the archegonium is known as the venter and the upper elongated portion as the neck. Neck initials tier divides by repeated transverse divisions to form a tube-like neck. The development of antheridium starts from a superficial antheridial cell, situated on the ,ife surface of the thallus Fig.
Riccia Structure, Life Cycle, Sexual and Asexual Reproduction
It is called octant stage Fig. O article is about the plant Riccia. Primary androgonial cells divide be several repeated transverse and vertical divisions resulting in the formation of large number of small cubical androgonial cells Fig.
Simultaneously the primary axial small cell divides transversely and unequally to form small upper primary cover cell and large lower central cell Fig. One flagellum serves for propulsion and the other for rotation and for changes in direction Fig. However, in Riccia personii four spores are iso-bilaterally arranged. Formation of rhizoids is affected by light intensity. The central cell divides Producing an egg or roccia towards the base and a small ventral canal cell towards the upper side.
In aquatic form of Riccia fluitans epidermis is continuous and air chambers are almost completely closed. Rhizoids are nearly lacking in aquatic forms, but there are usually numerous unicellular rhizoids of two types on the ventral surface. In certain species R. It consists of compactly arranged parenchymatous cells. The cells chcle the amphithecium divide only by anticlinal division to form a single-layered sterile jacket or capsule wall.
It lacks foot and seta Fig. The central cell divides into an upper primary neck canal cell and a lower venter cell.
Riccia Ms. Inderveena Sharma H.O.D. Botany Department
It is a few cells away from the apical cell. The cells of the amphithecium by further anticline! Periclinal divisions ticcia take place in these octants producing outer ricia initials and inner androgonial initials. Germinal tube is filled with cytoplasm which contains albumin granules, chloroplasts and oil granules. Majority of the species of this genus are terrestrial but some species are aquatic as these are found growing actually in the water.
A wall is then secreted around the oospore. These octants divide further producing a group of about cells. The male and female nuclei fuse together producing a single diploid nucleus. Some hairy epidermal outgrowths are also seen lfie Riccia melanospora, though rarely Fig.
Its cells divide and re-divide to form a mass of sporogenous cells sporocytes, Fig.

It has a single-layered capsule wall which encloses spores.
