The entire structure is covered from the base by five spirally twisted tube cells except at the apex, where they form a crown made up of five corona cells (Fig. It consists of centrally placed one central cell, one stalk and one large egg at the top (Fig. Like globule it is also developed at the node of primary laterals just above the globule in homothallic species.
The nucule of Chara is oval with a short stalk. Thus a globule can develop as much as 20,000 to 50,000 antherozoids. 3.95J, K) forms a biflagellate, coiled and uninucleate antherozoid (Fig. Each antheridial filament has 25-250 cells and each cell i.e., antheridium (Fig. Each primary capitulum develops two or more secondary capitula.įinally each secondary capitulum develops 2-4 long antheridial- filaments (Fig. At the distal end of each manubrium one or more globose cells developed are called primary capitula. Each globule consists of eight curved plates, situated towards the outer side, which are the shield cells.įrom the inner side of the each shield cell, a centrally placed rod shaped structure is developed, called the manubrium. Mature globules are spherical in shape and yellow to red in colour (Fig. Most of the species are homothallic or monoecious (i.e., male and female sex organs develop on the same plant), but some are heterothallic or dioecious (e.g., C. Nucule is always situated singly above the globule (Fig. They develop on the nodes of the branch of limited growth (i.e., primary lateral), intermingled with secondary laterals. The female sex organ is more or less oval and green in colour, called the nucule or oogonium. The male sex organ is spherical and yellow to red in colour, called globule. The sex organs are macroscopic and large. Sexual reproduction of Chara is an advanced oogamous type. New plants are also developed from the secondary protonema. These are thread like structures developed from primary protonema or from the basal cell of the rhizoid. The amylum stars are developed at the nodal cells of the basal region e.g., C. These are multicellular aggregations of cells, looking like stars and the cells are densely filled with amylum starch thus they are called amylum stars.
On being detached from the mother plant, they germinate and develop into new plants (Fig. These are small cells developed and aggregated at the node, called amorphous bulbils. After detachment, they germinate and develop new plants (Fig. These are small oval or spherical bodies developed on stem or root nodes. The vegetative reproduction takes place by the formation of following structures: Reproduction in Chara:Ĭhara reproduces by both vegetative and sexual means. During germination, zygote undergoes meiosis and gradually it forms the plant body of Chara. It shows very much elaborate post-fertilisation changes.Ĩ. Zygote is produced after sexual reproduction. The nucule is oval-shaped and very much protected, which contains one egg and globule is round and develops many antherozoids. Vegetative reproduction takes place by means of specialised star-like, tuber-like and protonema-like structures.ħ. Reproduction is of two types: Vegetative and Sexual.Ħ. The upper one remains as apical cell, middle biconcave one forms the nodal initial and the lower one forms the internodal initial.ĥ. The cell undergoes repeated transverse divisions and form a row of three cells (Fig. Growth of Chara takes place by a dome- shaped apical cell. The cytoplasm is differentiated into outer ectoplasm and inner endoplasm. The internodal cells are long, with a large central vacuole, many nuclei and many discoid chloroplasts in the cytoplasm. Small vacuoles may be present in the cytoplasm.
The nodal cells are short, uninucleate, with dense and granular cytoplasm and many discoid chloroplasts without pyrenoids. braunii, and diplostephanous (i.e., stipules are arranged in two rows) e.g., C. baltica):ĭepending on the arrangement of stipulodes species of Chara are divided into haplostephanous (i.e., stipules are arranged in single row) e.g., C. coralline) or if double it is called bistipulate (C. The number of stipufode at each node may be equal to the number of branchlets which is called unistipulate (C. These are unicellular outgrowths developed from lower nodes of branchlets i.e., branches of limited growth.