|
Selaginella Galotteii
''Selaginella'', also known as spikemosses or lesser clubmosses, is a genus of lycophyte. It is usually treated as the only genus in the family Selaginellaceae, with over 750 known species. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having spores of two types. They are sometimes included in an informal paraphyletic group called the "fern allies". The species '' S. moellendorffii'' is an important model organism. Its genome has been sequenced by the United States Department of Energy's Joint Genome Institute. The name ''Selaginella'' was erected by Palisot de Beauvois solely for the species ''Selaginella selaginoides'', which turns out (with the closely related ''Selaginella deflexa'') to be a clade that is sister to all other ''Selaginellas'', so any definitive subdivision of the species into separate genera leaves two taxa in ''Selaginella'', with the hundreds of other species in new or resurrected genera. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Anton Eugen Prantl
Karl Anton Eugen Prantl (10 September 1849 – 24 February 1893), also known as Carl Anton Eugen Prantl, was a German botanist. Prantl was born in Munich, Kingdom of Bavaria, and studied in Munich. In 1870, he graduated with the dissertation ''Das Inulin. Ein Beitrag zur Pflanzenphysiologie'' (The inulin, a contribution to the plant physiology). He worked with Carl Wilhelm von Nägeli and Julius Sachs. From 1887 on, he published ''Die Natürlichen Pflanzenfamilien'' (''The Natural Plant Families'') with fellow botanist Adolf Engler, who completed the work in 1915.Sambamurty, A.V.S.S''Taxonomy of Angiosperms.''I. K. International Pvt Ltd, 2005: Page 15-16. Accessed on August 10, 2011 In 1877, he became a professor at the forest educational institution at Aschaffenburg, transferring to Breslau University in 1889, where he also became director of the botanical garden there. Prantl worked particularly on Cryptogams. Works *''Lehrbuch der Botanik'' (Textbook of Botany), 7 Eds., Leip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selaginella Kraussiana
''Selaginella kraussiana'' is a species of vascular plant in the family Selaginellaceae. It is referred to by the common names Krauss' spikemoss, Krauss's clubmoss, or African clubmoss, and is found naturally in parts of Sub-Saharan Africa and in Macaronesia. It is sometimes given the misnomer of “peacock fern”, due to its lacy leaf structure, despite having no relation to actual ferns; rather, it belongs to the very ancient lineage of plants known as the clubmosses. Description Growing to just high, it is a low-growing, mat-forming evergreen perennial with primitive fern-like leaves, that spreads via rooting stems. Seginella kraussiana.jpg, Illustrating greener coloration when grown in brighter light Selaginella kraussiana OB10.1.jpg, Close-up of the foliage Distribution Its native distribution is the Macaronesia, and parts of south and east Africa. Its native distribution in the Azores was controversial up until 2005, when spores of this species were discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microphylls And Megaphylls
In plant anatomy and evolution a microphyll (or lycophyll) is a type of plant leaf with one single, unbranched leaf vein. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of a microphyll, the leaf vein emerges from the protostele without leaving a leaf gap. Leaf gaps are small areas above the node of some leaves where there is no vascular tissue, as it has all been diverted to the leaf. Megaphylls, in contrast, have multiple veins within the leaf and leaf gaps above them in the stem. Leaf vasculature The clubmosses and horsetails have microphylls, as in all extant species there is only a single vascular trace in each leaf. These leaves are narrow because the width of the blade is limited by the distance water can efficiently diffuse cell-to-cell from the central vascular strand to the margin of the leaf. Despite their name, microphylls are not always small: those of '' Isoëtes'' can reach 25 centimetr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cotyledon
A cotyledon ( ; ; "a cavity, small cup, any cup-shaped hollow", gen. (), ) is a "seed leaf" – a significant part of the embryo within the seed of a plant – and is formally defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." Botanists use the number of cotyledons present as one characteristic to classify the flowering plants (angiosperms): species with one cotyledon are called monocotyledonous ("monocots"); plants with two embryonic leaves are termed dicotyledonous ("dicots"). Many orchids with minute seeds have no identifiable cotyledon, and are regarded as acotyledons. The Dodders (''Cuscuta'' spp) also lack cotyledons, as does the African tree '' Mammea africana'' ( Calophyllaceae). In the case of dicot seedlings whose cotyledons are photosynthetic, the cotyledons are functionally similar to leaves. However, true leaves and cotyledons are developmentally distinct. Cotyledons form during embryo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selaginella Rupestris
''Selaginella rupestris'', the northern selaginella sometimes locally known as ledge spike-moss or rock spike-moss, is a species of spike-moss occurring in dry rocky places in eastern North America, including one locality in Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan .... It has a wide but sporadic range. In the absence of water, it rolls into a ball for which, it is also known as bird nest moss. Again, when it comes in contact with water, it opens up. It is listed as imperiled and threatened in the State of Indiana. References External linksFlora of North America rupestris Flora of Northern America Plants described in 1753 Taxa named by Carl Linnaeus Lithophytes {{Lycophyte-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterospory
Heterospory is the production of spores of two different sizes and sexes by the sporophytes of land plants. The smaller of these, the microspore, is male and the larger megaspore is female. Heterospory evolved during the Devonian period from isospory independently in several plant groups: the Lycopodiopsida, clubmosses, the ferns including the Equisetopsida, arborescent horsetails, and progymnosperms. This occurred as part of the process of evolution of the timing of Sexual differentiation, sex differentiation.Sussex, I.M. (1966) The origin and development of heterospory in vascular plants. Chapter 9 in ''Trends in Plant morphogenesis'', ed. by E.G. Cutter, Longmans. Four extant groups of plants are heterosporous; Selaginella, Isoetes, Salviniales and seed plants. Origin of heterospory Heterospory evolved due to natural selection that favoured an increase in propagule size compared with the smaller spores of homosporous plants. Heterosporous plants, similar to anisosporic plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligule
A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf A leaf (: leaves) is a principal appendage of the plant stem, stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leav ... and leafstalk of many grasses (family Poaceae) and sedges (family Cyperaceae). A ligule is also a strap-shaped extension of the corolla, such as that of a ray floret in plants in the daisy family Asteraceae. Poaceae and Cyperaceae The ligule is part of the leaf that is found at the junction of the blade and sheath of the leaf. It may take several forms, but it is commonly some form of translucent membrane or a fringe of hairs. The membranous ligule can be very short 1–2 mm ( Kentucky bluegrass, ''Poa pratensis'') to very long 10–20 mm ( Johnson grass, ''Sorghum halepense''), it can also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casparian Strips
The Casparian strip is a band-like thickening in the center of the root endodermis (radial and tangential walls of endodermal cells) of vascular plants (Pteridophytes and Spermatophytes). The composition of the region is mainly suberin, lignin and some structural proteins, which are capable of reducing the diffusive apoplastic flow of water and solutes into the stele, its width varies between species. In the root, the Casparian strip is embedded within the cell wall of endodermal cells in the non-growing region of the root behind the root tip.Taiz, L., Zeiger, Eduardo, Møller, Ian Max, & Murphy, Angus. (2015). Plant physiology and development (Sixth ed.). Here, the Casparian strip serves as a boundary layer separating the apoplast of the cortex from the apoplast of the vascular tissue thereby blocking diffusion of material between the two. This separation forces water and solutes to pass through the plasma membrane via a symplastic route in order to cross the endodermis layer. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trabeculae
A trabecula (: trabeculae, from Latin for 'small beam') is a small, often microscopic, tissue element in the form of a small beam, strut or rod that supports or anchors a framework of parts within a body or organ. A trabecula generally has a mechanical function, and is usually composed of dense collagenous tissue (such as the trabecula of the spleen). It can be composed of other material such as muscle and bone. In the heart, muscles form trabeculae carneae and septomarginal trabeculae, and the left atrial appendage has a tubular trabeculated structure. Cancellous bone is formed from groupings of trabeculated bone tissue. In cross section, trabeculae of a cancellous bone can look like septa, but in three dimensions they are topologically distinct, with trabeculae being roughly rod or pillar-shaped and septa being sheet-like. When crossing fluid-filled spaces, trabeculae may offer the function of resisting tension (as in the penis, see for example trabeculae of corpora c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylem
Xylem is one of the two types of transport tissue (biology), tissue in vascular plants, the other being phloem; both of these are part of the vascular bundle. The basic function of the xylem is to transport water upward from the roots to parts of the plants such as stems and leaves, but it also transports plant nutrition, nutrients. The word ''xylem'' is derived from the Ancient Greek word (), meaning "wood"; the best-known wood organism is plants, though it is found throughout a plant. The term was introduced by Carl Nägeli in 1858. Structure The most distinctive xylem cell (biology), cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called ''vessels''. Wood also contains two other type of cells: Ground tissue#Parenchyma, parenchyma and ground tissue#Fibres, fibers. Xylem can be found: * in vascular bundles, present in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protostele
In a vascular plant, the stele is the central part of the root or stem containing the tissues derived from the procambium. These include vascular tissue, in some cases ground tissue (pith) and a pericycle, which, if present, defines the outermost boundary of the stele. Outside the stele lies the endodermis, which is the innermost cell layer of the cortex. The concept of the stele was developed in the late 19th century by French botanists P. E. L. van Tieghem and H. Doultion as a model for understanding the relationship between the shoot and root, and for discussing the evolution of vascular plant morphology. Now, at the beginning of the 21st century, plant molecular biologists are coming to understand the genetics and developmental pathways that govern tissue patterns in the stele. Moreover, physiologists are examining how the anatomy (sizes and shapes) of different steles affect the function of organs. Protostele The earliest vascular plants had stems with a central core of v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
