They are mainly found growing in eastern as well as Western Himalayas and the hills of South India. 18). He also described the genus Diplostachyum to include a group of species similar to Selaginella apoda. Later on by further divisions it forms a multicellular structure which gets differentiated into foot, rhizophore, stem and cotyledons (Fig. 16 C, D). If it falls on suitable substratum, it germinates. A few cells near the apex of female prothallus behave as archegonial initials which by further divisions, give rise to archegonia (Fig. Content Guidelines 2. Before sharing your knowledge on this site, please read the following pages: 1. This turns out, today, to be a group of around 45-50 species also known as the Articulatae, since his genus Didiclis/Gymnogynum was based on Selaginella plumosa. These resting buds are capable to pass on the unfavourable conditions. Selaginella is a sporophytic plant (2x) and produces two different types of spores i.e., microspores and megaspores. Stachygynandrum is also sometimes used to include the bulk of species. 7A). It is a typical protostele. In megasporangium all the megaspore mother cells degenerate except one which divides reductionally forming a tetrad (Fig. Native to variable climates (including North Carolina) from tropical to dry and from sun to shade; the genus Selaginella is truly a diverse group. [citation needed] The stems contain no pith. The following views regarding the morphological nature of the rhizophore have been proposed: According to Harvey Gibson (1902), Uphof (1920), Wochok and Sussex (1974), the rhizophore is a capless root because: (iii) It is almost similar in anatomy of the root. References. spikemosses include: A few species of Selaginella are desert plants known as "resurrection plants", because they curl up in a tight, brown or reddish ball during dry times, and uncurl and turn green in the presence of moisture. The archesporial initials divide in all directions forming a group of cells known as sporogenous tissue. It grows quite low to the ground, with small, bright green leaves that often overlap one another. The bigger leaves alternate with bigger ones and smaller leaves alternate with smaller ones. Salient Features of Selaginella: i. This plant is pretty easy to grow as long as you don't let it dry out. Welcome to BiologyDiscussion! Related WordsSynonymsLegend: Switch to new thesaurus Noun 1. The life cycle is the shortest of the genus Selaginella, as well as one of the shortest among the lycophytes. On the adaxial side of the leaf, near the base is present a small membranous out-growth known as ligule. Trypanosoma Gambiense: Habitat, Reproduction and Life Cycle, Pteridium: Habitat, External Features and Reproduction. [citation needed]. Endodermis is followed by one to three layered pricycle. [3]:7 The plants are heterosporous with spores of two different size classes, known as megaspores and microspores. The stomata may be present on both the outer and inner epidermis. It is typically a protostele. Development of sporangium and formation of spores: As the position of sporangium is either cauline or foliar, the initials are either situated on the axis or on the leaf respectively. 10 F). It is found growing on tree trunks. Phloem, in turn, is surrounded by a single layered pericycle. to 20 meters. Each megasporangium is also a stalked but lobed structure and somewhat bigger than the microsporangium. Martinus Nijhoff, The Hague. [10] They show a wide range of characters; the genus is overdue for a revision which might include subdivision into several genera. Selaginella apoda: Sela01: Specifications: Selaginella apoda: This Selaginella is a real must for all plant enthusiastics. The antheridial cell divides vertically (2-2) to the prothallial cell to form the two primary cells of the antheridium (Fig. In some species of Selaginella (e.g., S. apus and S. rupestris the megagametophytes arenever shed from the megasporangium and remain on the strobilus. The plants are heterosporous i.e., produce two different types of sporesmegaspores and microspores. The cells of the epidermis are provided with chloroplasts. lyalli). 12 D). Selaginella is the only living genus of the order Selaginellales and is commonly known as spike moss or small club moss. 11 D, E). Xylem is usually made of tracheids. This website includes study notes, research papers, essays, articles and other allied information submitted by visitors like YOU. Under humid conditions in S. rupestris, trailing branches of the stem develop adventitious branches. It is 1 (monostelic e.g., S. spinulosa), 2 (distelic e.g., S. kraussiana) or 12-16 (polystelic e.g., S. laevigata). Selaginella apoda (L.)C.Morren var. The megaspores are much larger than microspores, 1.5 to 5 millimeter in diameter, tetrahedral in shape and show triradiate ridge. In case if for whatever reason we cant get the plants within the 15 working days your payment will be refunded. The sporangia usually dehisce by a vertical slit formed in apical region of the sporangia and the spores are disseminated in the air. The dimorphic condition of the spores is known as heterospory. Selaginella is a sporophytic plant (2x) and produces two different types of spores i.e., microspores and megaspores. In the young sporangium inside the wall is present a mass of sporogenous cells which in due course of development separate into microspore mother cells and later on by meiotic divisions produce numerous haploid tetrads of microspores. The whole plant is astringent and haemostatic [147]. Lycopodioides would include the North American species S. apoda and S. eclipes, while Bryodesma would include S. rupestris (as Bryodesma rupestre). In the sub-genus homoeophyllum all the leaves are of same size and are spirally arranged forming a dense covering. A Tranverse section (T.S.) This plant has no children. Water is necessary to carry out the process of fertilization. At maturity the tapetal cells as well as the inner wall of the microsporangium disorganizes i.e., wall of the sporangium is usually one layered at maturity. The leaves in this region are closely arranged and overlap the growing points. 1 A, C): It is usually profusely branched, delicate and evergreen. Primary androgonial cells divide and redivide to form 128 or 256 androcytes or antherozoid mother cells. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having spores of two types. The stems are aerial, horizontally creeping on the substratum (as in Selaginella kraussiana), sub erect (Selaginella trachyphylla) or erect (as in Selaginella erythropus). The sporophyte is an evergreen, delicate herb. The dehiscence of megasporangium is similar to that of microsporangium. First the nuclei are equally distributed in the cytoplasm but later on more nuclei collect in the apical region. Threatened and Endangered Information: This plant is listed by the U.S. federal government or a state. At this stage wall formation starts from the apical region downwardly thus forming an upper cellular region known as female prothallus and a lower non-cellular region known as storage region. Later on these microspores separate from each other. In S. inaequalifolia (Fig. For best results grow in rich, moist to wet soil in shade. 11 D) of 4 haploid megaspores. A T.S. It is usually not well defined but in some species as for example, S. densa, it is a distinct structure and only one cell in thickness. The microspores at maturity separate from each other. According to Worsdell (1910), Williams (1937), Cusic (1954) etc. It is a reproductive structure formed by the aggregation of ligulate sporophylls at the apex of the branches of stem. eclipes (see discussion) and S . Megaspores are larger in size than microspores (Fig. A mythical thug for a shady spot where it can spread and display its fragrant white flowers in Spring. pilifera Aberle Lycopodium apus Gmel. These antheridial cells are arranged in such a manner that four cells are present in the middle and two cells are present on either side i.e., above and below. of strobilus shows that it is a very simple structure. It may be tongue shaped (e.g., S. vogelii), fan shaped (e.g., S. martensii), fringed (e.g., S. cuspidata), or lobed (e.g., S. caulescens). The first major attempt to define and subdivide the group was by Palisot de Beauvois[4] in 1803-1805. Two primary cells thus formed divide transversely (3-3 Figs. Life Cycle Patterns. The swimming antherozoids reach the egg through the neck of archegonium and the nucleus of antherozoid fuses with the egg nucleus thus forming a zygotic nucleus. The parenchymatous cortex is usually made up of angular cells i.e., without intercellular spaces but in some cases the cells are rounded and provided with a few inter-cellular spaces. All the megaspore mother cells accept one degenerate. In S. kraussiana the gametophyte is shed at this stage. Additional information about this plant will become available later. It is made up of many large and small cells. Lycopodioides apoda (L.) Kuntze CT, MA, ME, NH, RI, VT; nearly throughout but absent from most of ME and northern NH. The middle four cells divide by periclinal walls (6-6, Fig. There is no definite wall of venter. In some species e.g. By the drying of unsplitted portion, the spores are forced out and then they are dispersed away by wind. S. intermedia the egg develops into embryo without fertilization. At maturity the neck canal cell and the ventral canal cell disorganize and absorb water which creates a pressure to separate apart the cover cells (Fig. 19, 20). 14 B-E). The remaining one later on by meiotic division produces only 4 haploid megaspores. In this way 6 cells are formed and microgametophyte has seven cells at this stage (4+ 2+1 cells). What are complement proteins? The roots are provided with root caps and root hairs. Thus, it is altogether a new structure. Small leaves are present on the dorsal side of the stem and bigger ones on the ventral side of the stem (Fig. In this way the sporophytic and gametophytic generations alternate with each other although the sporophytic phase is dominant over gametophytic phase (Figs. It occupies a wide zone between upper and lower epidermis. The cortex may be either wholly made up of thin walled parenchymatous cells or there may be sclerenchymatous outer cortex (hypodermis), 3 to 5 celled in thickness and parenchymatous inner cortex. 15). Verdoorn, F., ed. In other words we may call it as heterosporous plant. According to Goebel (1905), Bower (1908), the rhizophore is an organ Suigeneris i.e., having absolutely no parallel structure anywhere in the plant kingdom. SELAGINELLA APODA Meadow Spike Moss (We formerly sold this one as Selaginella 'Queen of Siam' Selaginella is a fern relative. The PH value for the soil should be around 5 to 6 for Selaginella apoda. It may be a water secreting or water absorbing or protective organ. 16 G). Ova stranica je posljednji put izmijenjena na datum 8 maj 2020 u 23:57. 9 D). Master ID: 31381: Species ID: 5778: Flora Disclaimer: The information in this website has been compiled from reliable sources, such as reference works on medicinal plants. The leaves ovate to elliptical, 5-10 cm long, acute to acuminate tip, green, smooth, slightly shiny upper surface, margins entire, leaves opposite, simple. In few species the rhizophore is present e.g., S. krciussiana while in others it is absent e.g., S. cuspidata. Its colour varies from red, yellow to brown in different species. It also looks like a moss, but is not. This structure arises from the prostrate axis at the point of dichotomy and elongates downward. These spores on germination produce male and female gametophytes (x) respectively which in turn developing upon the strobilus of parent produce antherozoids and egg in antheridia and archegonia respectively. ludoviciana have been reported (P. Somers and W. R. Buck 1975; T. R. Webster 1990). At maturity the tapetal cells usually along with inner wall of the sporangium disorganise.