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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In India lire in polyploid species gaugetica Udar and Chopra reported 24 n and 48 In chromosomes number. Water helps in the dehiscence of the anheridium. After fertilization the diploid zygote or oospore enlarges until it completely fills the cavity of the venter of the archegonium.
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The storage region is formed of compactly arranged parenchymatous cells which cyycle either colourless or contain only few chloroplasts, but these cells are rich in starch grains. These antherozoids come up to dorsal surface of ricia thallus from the antheridial chamber where they swim in the thin film of water and reach the mouth of the neck of the archegonium. The adventitious branches develop from the ventral surface of the thallus in species like Riccia fluitans.
The basal cell divides further producing the basal part live the antheridial stalk which remains embedded in the thallus tissue. However, in the terrestrial form of this species each air chamber opens on the upper surface by a small opening Fig. This sporogonium is not differentiated into foot, seta and capsule as in other liverworts.
Riccia Ms. Inderveena Sharma H.O.D. Botany Department
Riccia plants may be monoecious or dioecious depending upon the species. The cells of the amphithecium by further anticline! Antheridial chamber, in which an oof lies, communicates with the clorsal surface of the thallus by terminal opening.
The cells of inner layer of the venter wall the sporogonial wall along with some spore mother cells disorganize producing a viscous liquid.
From Wikipedia, the free encyclopedia. The student’s handbook of British hepatics, p. Antheridia and archegonia remain enclosed with in the antheridial and archegonial chambers and develop on the dorsal surface of the thallus Fig. The dorsal surface is light green or dark green body, each branch having a thick midrib.
On being detained, these branches develop into new thalli Fig.
In the monoecious species the antheridia are generally produced earlier than the archegonia. The thallus of Riccia has a simple structure and is formed of parenchymatous cells which are bounded on both sides by the upper and lower epidermis. In Riccia fluitans, the only aquatic species, thallus is long, narrow, ribbon-like and dichotomously branched. A bilayered calyptra forms a protective covering around the capsule. Tubers are common in Riccia discolor, R.
Riccia – Wikipedia
cydle Sex organs lie embedded in the mid dorsal section of the thallus between air spaces and filaments. Both the androcytes remain enclosed in the wall of the androcyte mother cell with one separate wall Fig.
In this article we will discuss about the g ametophytic phase, reproduction and sporophytic phase in the life cycle of riccia. In this way the primary axial cell gets surrounded by six cells Yccle. It is the most common method of vegetative reproduction in Riccia.
Riccia Ms. Inderveena Sharma H.O.D. Botany Department – ppt video online download
In other projects Wikimedia Commons Wikispecies. Transition onto Land Advantages of living in the water included… 1. In spongy thallus of Riccia crystallina the assimilatory or photosynthetic cells form a loosely- arranged network enclosing large air spaces. Rhizoids and scales serve as anchors for the plant. Twelve to twenty cells in perimeter enclose a small venter canal cell and large egg.
The spores are haploid as these have been produced after the reduction division in the spore mother cells. Rhizoids are numerous, unicellular, elongated, tubular and hair-like and are found as simple rhizoids or tuberculate rhizoids.
In certain species few sport mother cells do not produce spores but disorganise producing a mucilaginous fluid, The original wall of the sporogonium disorganises producing a mucilaginous fluid before the maturation of spores. The spores are tetrahedrally arranged Fig. Its upper dorsal surface is green and chlorophyll -bearing, with a mid-dorsal longitudinal sulcus furrow or groove.