Necessary cookies are absolutely essential for the website to function properly. According to this theory the simple sporophyte of the liverworts evolved into an elaborate and a complex structure along the following lines: Morphological nature of annulus is controversial. Sori are round to elongate and borne at the junction of two or more veins. Certain species of Selaginela propagate by bulbils or by smaller tubur as in S. chrysocaulos and S. chrysorrhizos. The best answers are voted up and rise to the top. Each sporangium, which dehisces by means of a terminal slit, produces numerous tetrahedral spores (Fig 6.15). Pinna is short-stalked and pseudo-dichotomously branched. A T.S. Leaves unipinnate, sporangia borne on vascular commissures adjacent to midrib as coenosori. Most of the species have strobiloid reproductive structure. After divisions oospore develops, into embryo or sporophyte. Pinnae bear free veins with costal areolae. Strobilus definition, a reproductive structure characterized by overlapping scalelike parts, as a pine cone or the fruit of the hop. Sporangia and paraphyses are grouped together in each sori. Which part of the male reproductive system store the sperm? Annulus obliquely vertical with stomium dehiscing by transverse split. Sporangia are aggregated into a small strobilus (5 7 mm in length) and situated at the tip of all aerial branches. Although there are several archegonia in the prothallus, only one is fertilized. Hymenophyllum 12. 3. The microspores are bilateral, lenticular while the megaspores are tetrahedral (Fig 6.10). Lycopodium is homosporous, i.e., all spores are of the same type. In T.S. What do you mean by permeability of membrane? (c) The innermost cortical layer, i.e., endodermal layer is modified into tubular trabeculae. A periderm is present at the periphery of the broad cortex. It consists of annular and spiral tracheids. It terminates a fertile shoot and is composed of whorls of stalked sporangiophores with peltate sporangia. Botany, Pteridophyta, Equisetum, Anatomy of Equisetum. Sori are located on terminal part of the leaf segments of upper pinnae; lips of indusium always well developed. Less developed chlorenchyma and sclerenchyma regions. In each mature sporangium there are a few transverse plates called trabeculae which incompletely divide the cavity within the mature sporangium. Which types of bacteria are used in Bt-cotton? The plant has an erect stem axis with branches. Lygodium 9. Median leaves are serrulate, axillary leaves denticulate. Sori are ex-indusiate. 245, 246). Plants homosporous, leaf 1-2 pinnate, sporangia in sori on the ventral side of the leaf, sporangia with indusium, sporangial development gradate or mixed. Cyathea 11. There are oval, bean-shaped rounded to squarish and usually formed in a cluster of a few to many; A longitudinal horizontal section of the sporocarp cuts each sorus transversely and it is seen that each sorus is elongate, covered by a delicate indusium, gradade basipetal in arrangement with a row of larger sporangia (mega-sporangia) on top and two rows of smaller sporangia (microsporangia) on two sides. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. This cookie is set by GDPR Cookie Consent plugin. Sporophyte differentiated into stem, leaf and root, stem jointed, siphonostelic; xylem exarch or endarch; sporangia borne oti specialised stalk (sporangiophore) which are organised into strobili, homosporus. The single extant genus of Equisetophyta, Equisetum, produces strobili in which the lateral organs are sporangiophores. Microspores are many per sporangium, while megaspores are larger and only a few per sporangium. Plant herbaceous with definite strobilus. Sori are marginal to the famine, lies on a vascular commissure between the apex and sinus of a segment. The cookie is used to store the user consent for the cookies in the category "Analytics". It also resembles in structure with the aerial stertile shoot except a few following dissimilarities: 1. 1. Each mature sporangium has a long slender multicellular stalk and number of spores enclosed in the capsule wall may be 64 or less. In each sunken stoma, the guard cells are covered completely by subsidiary cells, thus giving the appearance of two sets of guard cells. In different species the stellar type varies distinctly. The cortical tissue is bounded inwardly by the endodermal layer which shows casparian strips on the radial walls. The plant has long, creeping dichotomously branched rhizomes clothed with scales or hairs. Leaves are all microphyllous. A T.S. The upper surface of floating leaf is papillose to hairy. Epidermis is single-layered and covered with cuticle. Habit and Habitat of Lycopodium: Lycopodium is commonly known as 'club moss' due to their moss like appearance and club shaped strobili. Lamina is unipinnate, with entire pinnae. Sporophylls are lanceolate to ovate. The sporangia are developed in strobilis, which are terminal and slender. This cookie is set by GDPR Cookie Consent plugin. Can cockroaches be fused together with their Brain Juice? Each sporophyll bears a sporangium on its adaxial surface. In the species, where cortex is homogeneous, it consists of parenchymatous cells. Introduction to Pteridophytes: Pteridophytes constitute a significant and important group in the plant kingdom. similar and under suitable conditions give rise to gametophyte which bears antheridium and archegonia. Our mission is to provide an online platform to help students to share notes in Biology. Next to the pericycle is present the stele. through rhizome shows massive cortex, central pith and siphonostelic vascular cylinder with leaf traces. Fertile aerial, unbranched shoots bear at their apices (Fig. The plant has a short erect stem with branches without any hairs. 3 Modes of Reproduction found in Rhodophyceae or Red Algae. Pinnae have free veins. It shows an epidermis of one layer thickness with scattered stomata. 8. The central stem produces bracts and in the axil of each bract is a cone scale. This website uses cookies to improve your experience while you navigate through the website. Stem with scales, sori marginal at the apex of the vein tips, non paraphysate, and spore surface ornamented. Strobili are often called cones, but some botanists restrict the use of the term cone to the woody seed strobili of conifers. Sporangia borne in roundish to elongate linear, abaxial sori, or rarely also on the leaf tissue, indusiate, indusium reniform, sporangia stalked, annulus vertical. distance below the strobilus. Sori are non-paraphysate and covered by an abaxial indusium. Lycopodium 3. Lycopodium 3. Plant body differentiated into rhizomatous stem, leaf and root, leaf megaphyllous, sporangia aggregate mostly on the leaf margin as sori. Pteridophytes have a long geological history on our planet. Stele is of ectophloic siphonostelic type. Similarly the small spores are microspores formed in microsporangium borne on a microsporophyll. These are transversely barred. The laminar flange that covers each sporangium serves as an indusium. Stem with distinct scales, spore monolete, pinna stalks continuous with the rachis. Plants homosporous, leaf 1-2 pinnate, sporangia in sori on the ventral side of the leaf, sporangia with indusium, sporangial development mixed. It does not store any personal data. Cut thin transverse sections of stem, leaf and root by inserting the material in pith, stain in safranin- fast green combination, mount in glycerine and study- under microscope. If a cluster of sporophylls terminate a shoot thisconstitutes a strobilus. It is formed by the aggregation of sporangia bearing sporophylls. This cookie is set by GDPR Cookie Consent plugin. 237,238). Sporangia lie on two sides of the midrib of the pinnules. 2. through sporangium it appears that each lobe contains a spore chamber with numerous spores within a multi-layered wall. This cookie is set by GDPR Cookie Consent plugin. Blechnum 15. At the tip of each branch there is a sporangiferous spike or strobilus. A T.S. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. Sporangia are borne in clusters forming sori. 2. The plant bears long, slender and creeping stem which is covered by clathrate scales and many fibrous roots. This cookie is set by GDPR Cookie Consent plugin. Lamina are simple with free to somewhat anastomosing veins. Sori with long paraphyses, indusiate; spores tetrahedral, globose, trilete, surface verrucate. These cookies ensure basic functionalities and security features of the website, anonymously. The young embryos develop within the wall of megasporangium and drop out as soon as they develop a root and primary shoot. Give an example. Updates? Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. In a few species such as Selaginella and Equisetum, the sporophylls form compact structures called cones or strobili. of the internode of a mature stem reveals a protoxylem lacuna (carinal canal) associated with a vascular bundle. Paraphyses are branched with- an enlarged apical cell. When capsule is mature and dry, spores are thrown out. Terms of Service 7. Sporangia stalked, 2 rowed and bear vertical annulus. Leaves are monomorphic, and borne as loose clusters on the stem. Account Disable 12. The strobilus is either erect or horizontal. Strobili are characterized by a central axis (anatomically a stem) surrounded by spirally arranged or decussate structures that may be modified leaves or modified stems. Sporangia are borne in the axil of some leaves and there are distinct sterile (vegetative leaves) and fertile (sporophylls) patches on the stem. 3. The dimorphic condition is known as heterospory. Share Your Word File The plant is terrestrial with long creeping stem. In other lycophytes, ordinary foliage leaves can act as sporophylls, and there are no organized strobili. Privacy Policy3. Draw a neatly labeled diagram of chloroplast found in leaf, and its role in photosynthesis? The sporangia, instead of being all alike, are of two distinct kinds. This cookie is set by GDPR Cookie Consent plugin. Veins anastomosing, sori sunken and very long near each margin, paraphyses with an enlarged apex. The plant is terrestrial with long creeping and slender stem bearing scales and fibrous roots. Sporangia borne on a long inframarginal commissure, sporangia borne in round to elongate sori, immature sori covered by stalked, peltate, roundish paraphyses ; spore ellipsoidal, monolete. Each cone or strobilus has a thick central axix known as strobilus axis or cone axis (Figs. Pollen strobili of Pinophyta are similar to those of cycads (although much smaller) and Ginkgoes in that they are composed of microsporophylls with microsporangia on the abaxial surface. A triradiate ridge is prominent on the top of the tetrahedral structure (Fig 6.8). These cookies ensure basic functionalities and security features of the website, anonymously. The sterile leaves are 3 lobed. Stem is short to long, creeping, slender and frequency branched. Receptacle is globose to elongate with short to moderately long paraphyses, indusium hemitelioid to sphaeropteroid. Upper chlorophyll containing cellular lobe with palisade and stomata above and below a cavity containing endophytic alga, Anabaena azollae. The latter consists of two layers. 231), present at the apices of the branches. Answer Now and help others. Spores are elliptical, monolete, slightly papillate to smooth and homosporous (Fig 6.22). Huperzia selago (L) Bernh. A T.S. (b) A few layers of angular parenchymatous cortex usually without intercellular spaces. In pteridophytes, megaspores are typically larger Read More In plant: Evolution of land plants from the Ordovician Period through the middle Devonian In some cases the strobili owing to the loose arrangement of sporophylls become, inconspicuous. Younger leaves show circinate vernation. Sporangia are aggregated to form strobilus. Stem ribbed, siphonostelic with endarch xylem, presence of conspicuous protoxylem lacunae (carinal canal), spores with elaters. Mature stem portion bears persistem leaf bases. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". Cycadophyta are typically dioecious (seed strobili and pollen strobili are produced on separate plants). Dr. Singh is known for his unique, focused and simplified NEET/AIIMS t. Outermost layer is the epidermis, cells of which have a deposit of silica in their outer and lateral walls. Sporangium is stalked and bears vertical to oblique annulus. Spores in the sporangium are arranged tetrahedrally. Both horizontal and aerial shoots are ribbed and differentiated into nodes and internodes. Stem surface covered with scales; sori devoid of true indusium, sori protected by leaf margin; sporangia stalked, annulus vertical, homosporus, spore trilete. A heterosporous life history occurs in some pteridophytes and in all seed plants. Sclerenchyma is excessively developed opposite the ribs. Lamina is simple, entire, glabrous and veins are free. Leaves are monomorphic megaphyllous and borne in a cluster. Their spermatozoon usually has 2 flagella (like mosses) but are sometimes also multiflagellate (like spermatozoa of other ferns). Leaves pinnate, entire, glabrous, sori elongate to long, sori borne on veins and indusiate; sori lie at wide angle or parallel to the veins; sporangia stalked, spores spheroidal and monolete. Most ancient pteridophytes appeared in Silurian period, they were . On the stem leaves are loosely arranged in spiral fashion. Archegonium is flask shaped and contain egg, ventral canal cell and neck cancel cell. Each spore has a triradiate ridge (Fig. through stem shows central siphonostelic core surrounded by endodermis, delicate cortex and epidermis. It has become familiar to millions through a diverse publishing program that includes scholarly works in all academic disciplines, bibles, music, school and college textbooks, business books, dictionaries and reference books, and academic journals. In this article we will discuss about the anatomy of lycopodium. Leaf epidermis often shows stomata. Plant body differentiated into rhizomatous stem, leaf and roots, leaf megaphyllous, sporangia aggregate mostly on the leaf margin as sori. Both microphylls and megaphylls can be sporophylls. Polystichum 19. Sori are marginal or sub-marginal, continuous as coenosori borne on vascular commissures connected with vein ends, being protected by reflexed leaf margin. Leaves distinctly ligulate; presence of trabeculated endodermal zone in the stem axis ; two types of sporangia with sporophylls, microsporangia with many microspores and mega-sporangia with a few megaspores. The sporangiferous spike develops at the junction of the petiole and the lamina. Leaves are monomorphic and borne in a cluster. Stem erect, creeping to scandent, with scales; Leaves pinnate, sori on veins, indusiate, indusium reniform, annulus vertical, homosporous, spore monolete and spheroidal. 11. It extends up to the epidermis in each groove, where lie the stomata. The cookies is used to store the user consent for the cookies in the category "Necessary". Leaves are microphyllous, linear and spirally arranged. These cookies will be stored in your browser only with your consent. Gnetophyta consists of three genera, Ephedra, Gnetum and Welwitschia. The plant has nearly erected to decumbent stem with scaly covering and fibrous soft roots. These cookies track visitors across websites and collect information to provide customized ads. The sporocarps are globose to ovoid, hairy when young, and borne in clusters near the base of the submerged leaf. Content Filtration 6. Below it there is a thick cortex traversed by leaf trace bundles. You also have the option to opt-out of these cookies. Strobili are long, cylindrical and pendent. Instead of a central pith cavity, a nodal diaphragm is present (Fig. The cookie is used to store the user consent for the cookies in the category "Other. What is a trophic hormone? In the centre of the sorus the vein ends in a placental tissue from which a number of sporangia arise without any order of development. Sunken stomata, located only in the furrows, are present. Each sporangiophore is umbrella-like in shape, with pendant sporangia (5 10 in number) attached to the underside of the polygonal, disc shaped shield of the sporangiophore. strobilus: [noun] an aggregation of sporophylls resembling a cone (as in the club mosses and horsetails). This condition is termed homospory and theclub mosses are homosporous. 4. Plant body differentiated into rhizomatous stem, leaf and root, leaf megaphyllous, sporangia aggregate mostly on the leaf margin as sori. Indusium formed by reflexed pinnae margin. It is a fertile leaf bearing reproductive structures. On germination, they develop into prothalli. Opposite each ridge is a vascular bundle of unusual interest. Isoetes 5. Omissions? The lamina is entire and lanceolate to ovate. Lateral leaves bear marginal sclerotic sheath. This website uses cookies to improve your experience while you navigate through the website. 7. Spores are ellipsoidal, monolete with prominent wing-like folds on surface (Fig. 245). Plants homosporous, leaf 1-2 pinnate, sporangia in sori on the ventral side of the leaf, sporangium with indusium, sporangial development gradate or mixed. The stem, as seen in transverse section, has prominent, alternately arranged ridges and furrows. 4. A T.S. Spores are ellipsoidal to somewhat spheroidal, monolete and surface more or less spinulose. They are slightly raised and ex-indusiate. Name the types of nitrogenous bases present in the RNA. Each leaf bears on its upper surface near its base one small membranous, tongue-like outgrowth called the ligule. 13. (With Methods)| Industrial Microbiology, How is Cheese Made Step by Step: Principles, Production and Process, Enzyme Production and Purification: Extraction & Separation Methods | Industrial Microbiology, Fermentation of Olives: Process, Control, Problems, Abnormalities and Developments. Lamina is unipinnate pinnatifid, more or less glabrous. At each node two rows of leaves are lateral and floating and the third row is submerged. (Lycopodium selago L.): It is small, dichotomously branched, erect herb with distinct root system. The plant body is thin, delicate and has pinnately branched rhizome with two rows of alternating leaves densely packed to overlap one another on the upper surface of rhizome. Cortex shows some leaf traces. xylem elements are arranged in star-shaped manner, which is surrounded by phloem. In Dryopteris adventitious buds arise in the axil of leaves and are detached from the plant and form new plants. Leaves (fronds) are monomorphic and borne in a cluster. Share Your PPT File. Plant body differentiated into rhizomatous stem, root and leaf, leaf megaphyllous, sporangia aggregate on the leaf margin as sori. Sporangia are mixed, stalked and devoid of paraphysis. A T.S. Stele is a protostele, which is triarch or tetrarch. Seed cones of many conifers are compound strobili. Each leaf has veins anastomosing without included free veinlets. All upper leaves are sporophyllous. Leaves compound, pinnate, sporangiferous spike branched with sporangia in two rows on the terminal branchlets. (Lycopodium cernuum L): It is small and somewhat prostrate herb and about 45 90 cm long. The stele is monarch, diarch or triarch with one, two or three protoxylem groups, 5. The reproductive structure is a compact one is Selaginella and develops at the terminal portions of branches. Sporophyte differentiated into leaf, stem and root, leaves microphyllous, each sporophyll bears one axial sporangia, proto-to siphonostelic type stem axis.
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