SphagnumSphagnum is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of Sphagnum can store water, since both living and dead plants can hold large quantities of water inside their cells; plants may hold 16 to 26 times as much water as their dry weight, depending on the species. The empty cells help retain water in drier conditions.
Physcomitrella patensPhyscomitrium patens, (synonym: Physcomitrella patens ) the spreading earthmoss, is a moss (bryophyte) used as a model organism for studies on plant evolution, development, and physiology. Physcomitrella patens is an early colonist of exposed mud and earth around the edges of pools of water. P. patens has a disjunct distribution in temperate parts of the world, with the exception of South America. The standard laboratory strain is the "Gransden" isolate, collected by H. Whitehouse from Gransden Wood, in Cambridgeshire in 1962.
ProtonemaA protonema (plural: protonemata) is a thread-like chain of cells that forms the earliest stage of development of the gametophyte (the haploid phase) in the life cycle of mosses. When a moss first grows from a spore, it starts as a germ tube, which lengthens and branches into a filamentous complex known as a protonema, which develops into a leafy gametophore, the adult form of a gametophyte in bryophytes. Moss spores germinate to form an alga-like filamentous structure called the protonema.
MonoicyMonoicy (mɒˈnoʊəsi) is a sexual system in haploid plants (mainly bryophytes) where both sperm and eggs are produced on the same gametophyte, in contrast with dioicy, where each gametophyte produces only sperm or eggs but never both. Both monoicous (mɒˈnoʊəkəs) and dioicous gametophytes produce gametes in gametangia by mitosis rather than meiosis, so that sperm and eggs are genetically identical with their parent gametophyte. It has been suggested that monoicy may have benefits in dry habitats where the ability to produce sporophytes is limited due to lack of water.
AglaophytonAglaophyton major (or more correctly Aglaophyton majus) was the sporophyte generation of a diplohaplontic, pre-vascular, axial, free-sporing land plant of the Lower Devonian (Pragian stage, around ). It had anatomical features intermediate between those of the bryophytes and vascular plants or tracheophytes. A. major was first described by Kidston and Lang in 1920 as the new species Rhynia major.
Gemma (botany)A gemma (plural gemmae) is a single cell, or a mass of cells, or a modified bud of tissue, that detaches from the parent and develops into a new individual. This type of asexual reproduction is referred to as fragmentation. It is a means of asexual propagation in plants. These structures are commonly found in fungi, algae, liverworts and mosses, but also in some flowering plants such as pygmy sundews and some species of butterworts. Vascular plants have many other methods of asexual reproduction including bulbils and turions.
DioicyDioicy (daɪˈoʊəsi) is a sexual system where archegonia and antheridia are produced on separate gametophytes. It is one of the two main sexual systems in bryophytes, the other being monoicy. Both dioicous (daɪˈoʊəkəs) and monoicous gametophytes produce gametes in gametangia by mitosis rather than meiosis, so that sperm and eggs are genetically identical with their parent gametophyte. Dioicy promotes outcrossing. Sexual dimorphism is commonly found in dioicous species.
RhizoidRhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be unicellular or multicellular. Plants originated in aquatic environments and gradually migrated to land during their long course of evolution. In water or near it, plants could absorb water from their surroundings, with no need for any special absorbing organ or tissue.
Plant cuticleA plant cuticle is a protecting film covering the outermost skin layer (epidermis) of leaves, young shoots and other aerial plant organs (aerial here meaning all plant parts not embedded in soil or other substrate) that have no periderm. The film consists of lipid and hydrocarbon polymers infused with wax, and is synthesized exclusively by the epidermal cells. The plant cuticle is a layer of lipid polymers impregnated with waxes that is present on the outer surfaces of the primary organs of all vascular land plants.
CryptogamA cryptogam (scientific name Cryptogamae) is a plant (in the wide sense of the word) or a plant-like organism that reproduces by spores, without flowers or seeds. The name Cryptogamae () means "hidden reproduction", referring to the fact that no seed is produced, thus cryptogams represent the non-seed bearing plants. Other names, such as "thallophytes", "lower plants", and "spore plants" are also occasionally used. As a group, Cryptogamae are the opposite of the Phanerogamae () or Spermatophyta (), the seed plants.
