![]() ![]() The one plant that is considered extinct in Canada is a moss. Individual plants are usually closely associated and several hundreds may be found in a single turf or cushion. Mosses occur in several growth forms, the more common being turfs, cushions, mats and wefts. ![]() Lacking true conducting tissues, mosses mostly absorb water directly through the stem and leaves. Most mosses can also reproduce by fragmentation, i.e., the breaking off of almost any plant part, which Reproduce asexually by gemmae (small groups of cells produced on the gametophyte tissues) or by bulbils (small, deciduous shoots) found in leaf axils. The sporophyte has a foot embedding it into the gametophyte and a spore capsule usually borne on a stalk (seta). Structures that attach the plant to its substrate), a simple or branched stem, and small leaves (mostly only one cell thick). Gametophyte plants produce sex cells (eggs, sperm) that undergo fertilization to produce another sporophyte. Some spores germinate into new gametophyte plants. The sporophyte produces spores that are wind dispersed. These are the free-living, perennial gametophyte (the typical green moss plant), and the short-lived sporophyte (asexual generation), which remains dependent on the gametophyte. Mosses show alternation of generations, i.e., have two phases in the life cycle. Potential by having a dominant gametophyte generation and by lacking specialized conducting tissues (a factor limiting size). Mosses are thought to be a reduced group, which lost much evolutionary Others argue that they developed from some green algal ancestor. Many botanists believe that mosses evolved from primitive vascular plants (i.e., those having true conducting tissues). Moss has rootlike structures (left) that attach the plant to the substrate and small leaves which are mostly one cell thick (right). ![]()
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