Morphology of Marsilea Systematic position Kingdom : Plantae - CEC

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Genus : Marsilea Linn. Common Name : Water Fern The plant body of Marsilea is sporophytic having diploid chromosome number in its somatic cells. During sexual reproduction, it produces male and female gametophytes, which are haploid in nature and form the sperm and egg, respectively. The sporophyte is differentiated into rhizome, roots, and leaves. Rhizome (Stem): The stem is a long and slender rhizome (Fig. 1). It creeps either on the surface like stolon, or slightly below the surface of the soil like rhizome. It grows extensively and is branched. The branches arise at the bases of petioles and are extra-axillary in position, arising in the lateral or oblique position. They run in all directions and may get rooted at the nodes. In this way, a single plant may cover an extensive area of about 20 metre’s diameter or even more. The stem is divisible into distinct nodes and internodes. The internodes are long in the hydrophytic species, and short in the sub-terrestrial or xerophytic species. Fig. 1 Creeping and slender rhizome of Marsilea sp.
Root: The primary root formed on the stem is short-lived and is soon replaced by adventitious roots, which arise gradually at the nodes on the underside of the stem (Fig. 1). Sometimes, roots may also arise at internodes (Marsilea aegyptiaca), or laterally (M. minuta). The roots are thin and may be branched or unbranched. They develop in an acropetal sequence, i.e. the youngest root is towards the apex of the rhizome. The number of roots at a node and their size vary considerably. Leaves: The leaves arise from the upper side of the stem and are arranged in two alternate rows (Fig. 1). They are long-petioled and compound. The petioles of the submerged plants are long, thin and flexible, with the lamina floating on the surface of water, while the leaves of plants growing in mud or on land have upright, short petioles, with lamina held in a spreading position. The lamina is usually divided into four leaflets of the same size. They spring from the tip of the petiole, so that the leaf apparently looks quadrifoliate. Occasionally, the number of leaflets may be 5 or 6, or even 8, instead of the usual 4. In outline the leaflets are obovate, elliptical, or wedge-shaped, with entire or dentate margins. According to Puri and Garg (1953), the leaf of Marsilea is pinnately compound, with four pinnules borne on the slender rachis; two pinnules are noticeably higher than the other two, and are inserted on the rachis in alternate fashion. A leaflet has many dichotomously branched veins, which are joined with each other by transverse bands and their ends unite to form marginal loops (Fig. 2).
Page 1: Morphology of Marsilea Marsilea, co
Page 5 and 6: Anatomy of Marsilea Rhizome (Stem)
Page 7 and 8: Leaflet Fig. 5 Marsilea:Transverse
Page 9 and 10: Vascular bundle lies within the end
Page 11 and 12: Fig. 8 Marsilea: different modes of
Page 13 and 14: cell for the second sporocarp. This
Page 15 and 16: its development. The outer cell of
Page 17 and 18: gametophyte, while prothallial cell
Page 19: produced within the fruit body, the

Morphology of Marsilea Systematic position Kingdom : Plantae - CEC

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