Ikkevaskulære

Ikkevaskulære is a term used in biology to describe organisms that lack specialized vascular tissues. These tissues, known as xylem and phloem, are responsible for transporting water, minerals, and nutrients throughout a plant. The absence of these vascular bundles means that non-vascular plants have a much simpler internal structure compared to vascular plants.

Instead of relying on a complex transport system, non-vascular plants absorb water and nutrients directly from their environment, primarily through their surfaces. This limits their size and typically confines them to moist habitats where they can readily access water. Reproduction in non-vascular plants also often depends on water, as their motile sperm need to swim to the egg.

The most common examples of non-vascular plants are bryophytes, which include mosses, liverworts, and hornworts. These organisms exhibit a dominant gametophyte generation, which is the haploid stage of their life cycle, and a dependent sporophyte generation. They lack true roots, stems, and leaves, instead possessing simpler structures like rhizoids for anchorage and structures that are analogous but not homologous to leaves and stems. Their ecological roles are significant, particularly in colonizing bare surfaces, contributing to soil formation, and providing microhabitats for other organisms.