Biological World

  Reproductive Structures of Pteridophyte The Pteridophyte sporophyte, besides being a prominent component of soil and vegetation, is an important ornamental plant in gardens and lawns. Indoors, its gracefulness and shape fit it ideally as a plant for pot culture in hallways and living rooms, especially during the months of November to March. Transportation of whole plants from one place to another without damage is attempted by packing them in sand, decomposed silt, ashes, or sawdust. Despite their rich horticultural value, many Pteridophytes are vanishing from nature due to indiscriminate destruction of their natural habitats and capturing of species for ornamental purposes. The best means of conservation is an adequate botanical knowledge of these plants, together with their habitats. The approaches of the non-destructive collection of herbarium specimens are now being stressed. The collection is also supplemented with data regarding the locality and habitat, so as to make it de...

Leaves of pteridophytes Leaves of pteridophytes are variously called phyllidia, fronds, foliage, or simply leaves. When metamorphosed to a leaf-stalk, it refers to a petiole. They exhibit the greatest diversity in size, shape, texture, form, and position. Leaves are primarily for photosynthesis, and many pteridophytic plants produce leaves of more than one kind, commonly termed as dimorphic . The following forms are commonly found among pteridophytes. 1. Elongate. In this case, the leaf is elongated but uniform in width at least for the greater part, the width tapering only towards the apex. The common examples are: Macrothelypteris torresiana, Oleandra wallichii, Pteris longifolia, Polyurhythmopityrhis bifida, and Cephalomanes biswasii. 2. Filiform or capillary. The width of the leaf bears only a very small proportion to its length. The common examples are: Stenochlaena palustris, Thelypteris acuminata, Tectaria braunii, Pteris kinabaluensis, Elaphoglossum pumilum, and Linochelium...

  Structures of Root of Pteridophyte The earliest diverging branched axes of extant vascular plants, lycophytes, are characterized by the presence of purely structural roots whose only function is anchorage, and these plant groups include forms with very complex rooting systems. The rooting structures of the most basal branch is a single unbranched rooting axis strongly resembling a root-like organizational strategy of geotropically-growing axes found in the common ancestor of mosses and liverworts. Aquatic rooted forms of this grade of morphological diversity became established in early prediluvial times when no earth surface was free from water. Structures on axes that carried out rooting functions in plants appeared very early in the evolutionary history of land plants. The earliest land plants did not have true roots as they are defined today, that is, as organs carrying out anchorage and absorption functions that developed from a root meristem covered with a root cap. Instead,...