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Soral & Sporangial Characters in pteridophytes.pptx
- 1. Soral and Sporangial Characters in Pteridophytes - A comparative account (https://th.bing.com/th/id/R.f407870c5eb7f427fe075c90de1e510d?rik=mHaijxcSeHv9fQ&riu=http%3a%2f%2fi1.treknature.com%2fphotos%2f482%2fff1.jpg&ehk=swnMZ%2fQnONqiBzoH0ckmgVsJzbudAKzbHSnKmZN%2fhn0%3d&risl=&pid=ImgRaw&r=0)
- 3. Sporangia •Spore bearing structure. •May be eusporangiate or leptosporangiate. •Homo- or Heterosporous. •Terminal/ Lateral/ aggregated into specialized structures. •Specialized structures may be sporophyll/ strobili/sporocarp/sorus. (https://i.pinimg.com/originals/98/92/bc/9892bc880bc70ff9c5cc81b22f9312f8.jpg)
- 4. Sporangia • Large sporangia are found in Ophioglossales & Marattiales. • The more primitive families of ferns: Osmundaceae, Gleicheniaceae & Schizaeaceae also have large sporangia but the walls are thin and annulus unspecialized. • The annulus is presumed to have originated by gradual differentiation within the surface layer until complete dimorphism of all types resulted. • Sporangia of Actinostachys, Schizaea, Stromatopteris and Osmunda show intergradation between surface cells and annular cells. (http://cupac.bh.cornell.edu/cupac_images/2013_02_08/0000031.21.tif.jpg) (http://cupac.bh.cornell.edu/cupac_images/2013_02_09/0000027.9.tif.j pg)
- 6. Dehiscence of a Sporangium • In the eusporangiate ferns, dehiscence is by a slit and is fundamentally longitudinal in all cases. • In the transitional family, Osmundaceae, Osmunda & Todea, The annulus is located near the tip but on to one side and forms a cleft that runs over the top of sporangium and down the opposite side. The sporangia opens like a clam. • In the leptosporangiate ferns, qthe annulus may form a cap at the distal end of sporangium as in Lygodium longitudinal dehiscence (https://th.bing.com/th/id/R.847257aa97cf9d9599adf6f434d58c6a?rik=KTZtRQSDMZAL9A&riu=http%3a%2f%2fpalaeos.com%2fplants%2fglossary%2fimages%2fAnnulusLygodium.jpg&ehk=LLST2hvjWErgWH0stEdFKo3%2bQAnpvMYcL%2b%2fSTVcIpTE%3d&risl=&pid=Im gRaw&r=0)
- 7. q be obliquely placed as in Gleichenia, Hymenophyllum & Loxsoma oblique dehiscence qRun over the top of sporangium in line with stalk i.e., in vertical position as in Leptochilus vertical dehiscence.
- 8. Development of sporangia Eusporangiate Leptosporangiate Transitional type https://th.bing.com/th/id/R.74b63b79d3cc1977102904640511417c?rik=pgzmWB5BMaEIrA&riu=http%3a%2f%2fbotit.botany.wisc.edu%2fResources%2fSystematics%2fLycopodiophyta%2fLycopodiales%2fLycopodiaceae%2fLycopodium%2fUndetermined+species%2fSporangium+ls+M C.jpg&ehk=bCKBSv3EKmW%2bhiPYbci%2f%2fuFsElXOlEsqhnGCq4EGNcI%3d&risl=&pid=ImgRaw&r=0, https://media.gettyimages.com/photos/pteris-50x-at-35mm-also-shows-spores-and-annulus-picture- id139802925, https://live.staticflickr.com/2692/4382051069_eae4a41938_b.jpg)
- 12. Lycopsida Protolepidodendrales Protolepidodendron Homosporous Lycopodiales Lycopodium Homosporous Isoetales Isoetes Heterosporous Selaginellales Selaginella Heterosporous Heterosporous & Homosporous Sporangia https://th.bing.com/th/id/R.b75bfe9a58decfa1911a26fbe7b5c08f?rik=FM%2fsOT0hoFVfSg&riu=http%3a%2f%2fwww.fernsoftheworld.com%2fwp-content%2fuploads%2f2014%2f04%2fP.-reflexus-stem- detail3.jpg&ehk=pYQgQlMH1b3pwLAMx0wnA8qyLJm3W7lRiiaYQl4jbuQ%3d&risl=&pid=ImgRaw&r=0, https://th.bing.com/th/id/R.a5bdde2f32aba807466cb255b2d75571?rik=VOVhOuMW8lBwBw&riu=http%3a% 2f%2fwww.discoverlife.org%2fIM%2fI_GY%2f0003%2f320%2fIsoetes_tegetiformans%2c_sporangia%2cI_GY366.jpg&ehk=3jqHVkdxSb7VQ1UxVHGVRi%2fiwvQAwW0S1ns0Yz3SAVI%3d&risl=&pid=ImgRaw&r=0, htt ps://i.pinimg.com/originals/10/b8/b0/10b8b00e70c3cb84c339048b208540de.jpg)
- 13. Psilopsida Rhyniales Rhynia Homosporous Psilotopsida Psilotales Psilotum Homosporous Sphenopsida Hyeniales Hyenia Homosporous Sphenophyllales Sphenophyllum Homo- /Heterosporous Calamitales Calamites Homo-/ Heterosporous Equisetales Equisetum Homosporous (https://live.staticflickr.com/2512/3703179043_43d63637f5_ b.jpg, https://th.bing.com/th/id/R.5928bd9543495d8c496790 97bb62d821?rik=OMI1HRJsGjxI2g&riu=http%3a%2f%2f4.bp.b logspot.com%2f- 6LSZIoMAMts%2fTpz5KfzscOI%2fAAAAAAAAAMY%2f93ZQHl2 oNGA%2fs1600%2f599px- Equisetum_hyemale.jpg&ehk=rbsSNh8s3f0hn6%2fZ9lZjR%2b y21E1ozlmrBM8eogxZqIA%3d&risl=&pid=ImgRaw&r=0)
- 14. Pteropsida Primofilicales Caldoxylales Cladoxylon Homosporous Ceonopteridales Botryopteris Homosporous Eusporangiatae Marattiales Angiopteris Homosporous Ophioglossales Ophioglossum Homosporous Osmundales Osmunda Homosporous Leptosporangiatae https://th.bing.com/th/id/OIP.fMs4h2C_p_dg5Mfnc1tKUQHaFj?pid=ImgDet&rs=1, https://www.researchgate.net/profile/GW_Rothwell/publication/12499957/figure/download/fig2/AS:601229768024073@1520355755914/Botr yopteris-tridentata-fertile-pinnules-sporangia-and-spores-A-Pinnule-wrapped.png, https://ebps.org.uk/wp-content/uploads/2017/06/DSC05034-768x461.jpg, https://i2.wp.com/mgnv.org/wp- content/uploads/2021/07/Sporangia_Osmunda_spectabilis_fertile_leaflets_May_MMF.jpg?resize=1536%2C1398&ssl=1)
- 15. Leptosporangiatae Marsileales Marsilea Heterosporous Salviniales Salvinia Heterosporous Azolla Heterosporous Filicales https://upload.wikimedia.org/wikipedia/commons/thumb/3/33/Marsilea_expanded_sporocarp.jpg/1024px- Marsilea_expanded_sporocarp.jpg, https://bugwoodcloud.org/images/768x512/5274062.jpg, https://th.bing.com/th/id/OIP.nI7LGLMrXbq0Nypq4il1yAHaFj?pid=ImgDet&rs=1)
- 16. Filicales Pteris Homosporous Lygodium Homosporous Acrostichum Homosporous Gleichenia Homosporous Adiantum Homosporous (http://4.bp.blogspot.com/_mFm838BFqBE/TSDLWupAjYI/AAAAAAAAA bI/Ejfgem- 5yQQ/s400/vittata8.jpg, https://edis.ifas.ufl.edu/LyraEDISServlet?comm and=getScreenImage&oid=5858944, http://www.nzflora.info/factsheet /images/Image1YX7large.jpg)
- 17. Lycopsida Protolepidodendrales Protolepidodendron Sporophyll Lycopodiales Lycopodium Strobili Isoetales Isoetes Sporophyll Selaginellales Selaginella Strobili https://th.bing.com/th/id/OIP.ulCW4RVvyUEdosU2eLeYAAHaE3?pid=ImgDet&rs=1, https://live.staticflickr.com/1439/1088012867_ac633a1de1_b.jpg)
- 18. Psilopsida Rhyniales Rhynia Sporangia Psilotopsida Psilotales Psilotum Synangia Sphenopsida Hyeniales Hyenia Sporangiophore Sphenophyllales Sphenophyllum Strobili Calamitales Calamites Sporangiophore Equisetales Equisetum Strobili (https://th.bing.com/th/id/R.645054f946d18b1e46b8e64033a82d15?rik=DWJTTu7cQq8zLA&riu=http%3a%2f%2ffern.la.coocan.jp%2fPsilotaceae%2fPsilotum+nudum%2fDSC05788.JPG&ehk=EsEHVg61ZC1y BnbGktPwohBVcKcgraTUi4WZRDUQPZU%3d&risl=&pid=ImgRaw&r=0, https://nyc.books.plantsofsuburbia.com/wp-content/uploads/2015/01/Equisetum-hyemale.-By-Donald-Cameron.-Copyright- %C2%A9-2015-Donald-Cameron..jpg)
- 19. Pteropsida Primofilicales Caldoxylales Cladoxylon Fan shaped sporangiophore Ceonopteridales Botryopteris Terminal sporangia Eusporangiatae Marattiales Angiopteris Sori on abaxial side of the leaves Ophioglossales Ophioglossum Sporangiferous spike Osmundales Osmunda Marginal Tassels Leptosporangiatae (https://tse3.mm.bing.net/th?id=OIP.otyl4nF0hunGfpOQzpqMAgHaE8&pid=Api&P=0&w=253&h=169, https://cdn.auckland.ac.nz/assets/nzplants/Ferns/Some%20Native%20Ferns/Ophioglossaceae/Ophioglossum%20biforme/5%20ophi oglos_pet_plt3a(PS7).jpg, https://i.pinimg.com/736x/36/db/a1/36dba13a90e3f3c3d00601cb1ec134e3--colours.jpg)
- 20. Leptosporangiatae Marsileales Marsilea Sporocarp Salviniales Salvinia Sporocarp Azolla Sporocarp Filicales (https://www.biophotosharing.com/getphoto.php?id=357, https://bugwoodcloud.org/images/768x512/5274062.jpg, https://www.wnmu.edu/academic/nspages/gilaflora/a_me xicana3.jpg)
- 21. Filicales Pteris Coenosorus Lygodium Monangial sorus Acrostichum Felt of sorus Gleichenia Sorus Adiantum Sorus (http://1.bp.blogspot.com/-iFACzjVJtPg/T0egQk59aVI/AAAAAAAAG1I/p3Y7dQ4_xkk/s1600/climbing-fern4- 033.jpg, https://biogeodb.stri.si.edu/bioinformatics/dfm/show_image.php?filename=25134&width=180&height=180, https://1.bp.blogspot.com/- lRkU8jUQPtA/T90l_d6m_VI/AAAAAAAADUc/jVRC8CXJYJ0/s1600/fasacascata23+soros.jpg, https://th.bing.com/th/id/R.02fe123b8723ecb5a866860973954eb1?rik=Aw2SL8a6qP%2fA0A&riu=http%3a%2f%2fw.natureloveyou.sg%2 fAdiantum+tenerum%2fDSC09406+(14).jpg&ehk=1XiY5ByVywGKBGe8dBMbRuVA5EQBqsj2k97TOiZw%2fTw%3d&risl=&pid=ImgRaw&r=0)
- 22. Sporangia in Rhynia • Borne singly on the apices of some aerial branches. • Each sporangium being oval or slightly cylindrical structure with a little greater diameter than that of aerial branch on which it is developed. • They were 12 mm long and 4 mm in breadth in R. major and 4 mm long and 1 mm broad in R. gwynne-vaughani. • Five cells thick wall. • 1 cell thick cuticularized epidermis was followed by 3 cells thick middle layers of thin walled cells. • The inner-most layer was 1 cell thick tapetum. • The wall was surrounding a spacious sporangial cavity. • Columella absent. • Homosporous with numerous spores. • No special mechanism of sporangium dehiscence. • The liberation of spores by disintegration of the sporangial wall.
- 23. Synangia in Psilotum • Eusporangiate development. • Synangium- fusion of 3 sporangia. • Borne on the axils of small leaf-like appendages. • Neither its outermost sporogenous cell nor the innermost jacket cells develop into the tapetum. • The spores formed in the tetrads are colourless and reniform. • Homosporous. (https://live.staticflickr.com/3094/3117458944_65d8090a24_n.jpg) (https://botit.botany.wisc.edu/Resources/Botany/Pteridophytes/Psilophytes/Psilotum/Synangium%20MC.jpg)
- 24. Sporangium in Protolepidodendron • On the middle part of the stem sporophylls are laxly borne intermixed with vegetative leaves. • The sporophylls resemble the vegetative leaves with bifurcate tips and bear single sporangia on the adaxial face is little above the bases. • No vascular connection leading to the sporangia.
- 25. Sporangial Characters in Lycopodium • Found singly on fertile leaves known as sporophylls. • Sporophylls bearing sporangia densely aggregated along stem to form either branched or unbranched called strobilus. • Strobili are terminal. • Reniform, orange to yellow. • Unseptate sac-like structure with a narrow or massive stalk. • Homosporous. • Eusporangiate development. • Dehiscence by transverse rupture of sporangium apex along the line of stomium. (https://asset.library.wisc.edu/1711.dl/STGCBU6ULSV2I8X/M/h1380-e86e1.jpg) (https://www.researchgate.net/profile/Alberto_Diego- Taboada/publication/260875436/figure/fig1/AS:296782396444675@1447769845877/Scannin g-electron-microscopy-SEM-picture-of-Lycopodium-clavatum-spores-showing.png)
- 26. Sporangial Characters in Isoetes • Heterosporous. • Largest among all known extant spore- producing plants. • Highest spore output. • 50-300 megaspores/ megasporangium. • 150,000-1000,000 microspores/microsporangium. • Sporangium traversed irregularly and incompletely by plate-like trabeculae. • Trabeculae surrounded by tapetum. • Microspores elongate, 45 microns long. • Megaspores 250-900 microns in diameter. (https://th.bing.com/th/id/OIP.pb3eLzKrqAdGbLJVstdVcQAAA A?pid=ImgDet&rs=1) (http://idtools.org/id/ aquariumplants/Aqua rium_&_Pond_Plants_ of_the_World/key/Aq uarium_&_Pond_Plan ts/Media/Images/Isoe tes-melanopoda-H- wilson_lge.jpg) (https://www.researchgate.net/profile/Paulo- Labiak/publication/272214264/figure/fig5/AS:670531535765526@1536878584817/SEM-images-of-the-spores- of-Isoetes-maxima-Pereira-et-al-631-UPCB-I-pedersenii.ppm)
- 27. • All leaves are potential sporophylls. • Sporophylls are ligulate. • Eusporangiate. • In microsporangia the sporocytes differentiate after the formation of trabeculae, while in megasporangia the sporocytes differentiate before the formation of trabeculae. • No dehiscence mechanism. • Spores are released only after the death and decay of the sporangia. (https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-echinospora-sc-blegler.jpg)
- 28. Sporangial Characters in Selaginella • Sporangia are produced on the axils of ligulated leaves called sporophylls. • The sporophylls are compactly arranged to form cones or strobili. • Heterosporous. • Eusporangiate. • Sporangia reniform to ovoid with a short stalk. • In microsporangia, all sporocytes except 10- 20% from form microspores. • Each sporangium has 2 layered wall, a layer of tapetum and sporogenous tissue. • Spores are with a prominent triradiate mark and characteristic ornamentation. (http://1.bp.blogspot.com/_mFm838BFqBE/TQFEUcH2-7I/AAAAAAAAAUY/Qq0xw6_OtX8/s1600/esporangios-selaginella.jpg) (https://tse1.mm.bing.net/th?id=OIP.eodQ88o23qLQAGIEsDz W9wHaFf&pid=Api&P=0&w=255&h=189) (https://www.researchgate.net/profile/Ivan_Valdespino2/pu blication/290156962/figure/download/fig3/AS:56392429075 2513@1511461436311/Selaginella-nanuzae-Valdespino-A- Megaspore-proximal-face-B-Close-up-of-megaspore.png) (http://www.sciencephoto.com/image/16797/large/B400009 8-Selaginella_moss_strobilus,_LM-SPL.jpg)
- 29. S. selaginoides Basal sporangium are non- functional. S. sulcata One meagaspore is produced S. rupestris Two megaspores are produced. S. helvetica Megasporangia at the base & microsporangia at the distal region. S. helvetica S. rupestris S. selaginoides: discharge of megaspores by "compression & slingshot ejection" (https://bio.libretexts.org/@api/deki/files/29958/InkedSelagi nella_strobilus_LS_high_LI.jpg?revision=1&size=bestfit&widt h=456&height=685)
- 30. S. oregana Megasporangia on one side and microsporangia on the other side. S. kraussiana One lower megasporangium and upper microsporangium. S. inequifolia Microsporangia on the left side and microsporangia on the right side. S. cuspidata The apex may continue vegetative growth beyond the formed strobilus and thus produces a shoot with sporophylls and foliage leaves in alternating zones along the stem. S. oregana S. inequifolia S. kraussiana
- 31. Sporangium of Hyenia • The sporangiophores were forked and the tips were reflexed which in turn terminated in two or three pendent sporangia.
- 32. Sporangia in Sphenophyllum • Strobili were borne at the tips of certain branches. • The strobili were either homo-/ heterosporous.
- 33. Sporangium in Calamites • Several types of strobili have been found on the fossil Calamitean type of plant body. • These have been assigned to the organ genera: Palaeostachya, Calaamocarpon, and Calamostachya. • In all strobili, whorls of peltate sporophylls alternated with whorls of lanceolate bracts. • Strobili were either homo- /heterosporous.
- 34. Sporangium in Equisetum • Reflexed sporangia are produced on sporangiophores which are aggregated into definite cones or strobili at the apex of fertile shoot. • Homosporous. • Eusporangiate. • Strobilus is composed of sporangiophores: an axis with whorls of stalked, peltate structures. Immediately below the whorls of sporangiophores, the axis bears a small or large ring like outgrowth, the annulus. • Each sporangiophore is umbrella like in shape. • 5-10 sporangia on the underside of each sporangiophore disc. Annulus Vestigeal remainder of Calamitean bracts. Sporangiophoric in nature, since it sometimes bear small sporangia. (https://live.staticflickr.com/895/2805 2498497_d2ba692831_b.jpg) (https://th.bing.com/th /id/R.3c58d8cb1fbca45 d006b2fedb525e7df?ri k=cPxiTXHzy41gtA&riu= http%3a%2f%2fwww.pl antsystematics.org%2fu sers%2fkcn2%2f4_22_0 4%2fUpEquisetum%2fE qui_arvense6.jpg&ehk= WUYQon%2bouoVQtxQ OYD8v%2fIlmfj9Xh1sdb 8AH7ihL4Ms%3d&risl= &pid=ImgRaw&r=0)
- 35. • Sporangia: slender stalk bearing a peltate and hexagonal disc on the under surface of which there are elongate, cylindrical hanging sporangia. • Each sporangium is an elongated, sac-like sructure attached to the inner side of stalked, sheild-shaped sporangiophore. • At first, the wall is 3-4 layered but when mature 2 jacket layers remain. (https://c2.staticflickr.com/6/5318/5883581480_32215 18fce_z.jpg) (https://upload.wikimedia.org/wikipedia/commons/thumb/7/77/Equisetum_arvense_spora ngia.jpg/360px-Equisetum_arvense_sporangia.jpg)
- 37. Spores of Equisetum • Spores are globular/ spherical in shape. • Thick wall with 4 concentric layers: Innermost cellulosic, delicate intine. Exine Middle layer Thick epispore • Intine and exine are products of spore-protoplast. • Middle layer & Epispore are formed around the intine & exine by the activity of the periplasmodium. • Epispore splits to 4 spirally arranged ribbon like bands called elaters, flattened at the tips. • The bands are free from the spore wall except for one common point of attachment. (https://i.pinimg.com/originals/59/bf/32/59bf326a69b49c18 545b2aca8f3f5ba8.jpg) (https://www.nirgal.net/microscopie/spore_prele_zstacking_big.jpg)
- 38. • The elaters are hygroscopic. • When moist, they are spirally coiled round the spore and uncoil and become extended as the spore dries out. • Elaters are different from those found in bryophytes. • When the spore matures, elaters uncoil and this expansion of the elaters help in the dehiscence of sporangium. • In shedding, these elaters uncoil, become entangled with the elaters of other spores and thus the spores are shed in groups rather than singly. • The elaters aid in spore dispersal. • The spores contain chloroplast. (http://www.missouriplants.com/images/Equisetum_hyemale_spores.jpg) (https://tse3.mm.bing.net/th?id=OIP.gh3gpsLFP77dMGbyjzzjGAHaFj&pid=Api&P=0&w=215&h=161)
- 39. • Sporangia are borne on unmodified foliage or on specialized fertile leaves. • Thick or thin walled. • Either terminal on the leaf segments but more commonly they are on the frond, marginally or superficially and rarely in specialized structures, the sporocarps. • Sporangia either single or form sori or fuse to form synangia. General Characteristics of Sporangia in Pteropsida
- 40. Sorus • The sporangia in higher ferns are aggregated in groups known as sori. • Sori may be circular to linear. • Positioned along the margin or towards the midvein (costa), surficial or in a groove or channel, etc. • In some cases, the developing sori are protected by a recurved leaf margin (false indusium), a covering of deciduous scales, or a more permanent small flap of tissue, the indusium. (https://rbg-web2.rbge.org.uk/thaiferns/factsheets/data/images/Adiantum_stenochlamys/thumbs/Adiantum_stenochlamys_Middleton_et_al_5221_PK_8269_sml.JPG)
- 41. Sorus • Indusia vary greatly in shape, size, texture and persistence, ranging from umbrella-shaped to globose to linear. • Sori may be variable in size, the larger ones result due to fusion, the coenosori. • The protion of the leaf surface bearing sporangia is termed as receptacle, it may be an elevated surface or a flat elongate structure. • Sporangia originate from the superficial cells of the receptacle. (https://i.pinimg.com/originals/12/cf/a3/12cfa3df749b572051e98ac93e4e99e0.jpg)
- 42. Coenosori may be broken up into segments as in Blechnum & Woodwardia. (https://live.staticflickr.com/4075/4822598915_b71f54b446_b.jpg) (https://live.staticflickr.com/130/377901147_39651a875d_b.jpg)
- 43. Felt & Marginal Tassels • If sporangia do not form sori, they are either scattered over the lower leaf surface forming a felt as in Acrostichum or marginal tassels over the surface of slender leaf divisions as in Osmunda or are solitary, along or close to the margins of narrow leaf segments as in Schizea and Anemia. (https://fernsofmacaronesia.org.uk/wp- content/uploads/2020/06/Osmunda-regalis-DSC04760B-768x512.jpg) (https://www.fernsoftheworld.com/wp- content/uploads/2014/05/Schizaea- elegans_PPDaniels_1047-1000x640.jpeg) (https://tse2.mm.bing.net/th?id=OIP.7qilqlhdjEUevrSL21RUpwAAAA&pi d=Api&P=0&w=206&h=158)
- 45. Marginal sorus: • Receptacle and sporangia originate from the margin of pinnae or pinnule. • The indusium, if present is a submarginal outgrowth around receptacle. • Indusium is funnel shaped or bilipped. • The two parts of the indusium may be different, often adaxial flap is thicker and histologically ressembles the leaf. • e.g., Hymenophyllum, Dicksonia, Culcita, Cibotium (https://c1.staticflickr.com/7/6068/6030902369_0ef8285b5a_b.jpg) (https://live.staticflickr.com/2644/3938743546_5c0e706374_b.jpg)
- 46. Intramarginal sorus: • The marginal cells often form a thin extension or loose meristematic activity. • The submarginal cells on abaxial side of the lamina become meristematic and form the receptacle or sporogenous meristem. • In some cases, a thin abaxial indusial flap is also formed from the surface cells near the meristem. • E.g., Cryptogramma, Pellaea, Pteridium, Adiantum (https://tse3.mm.bing.net/th?id=OIP.SapKwbGymNEAdl4ijg2drQAAAA&pid=Api&P=0&w=158&h=158, https://tse1.m m.bing.net/th?id=OIP.L3yBoGzBjN8opUylrgntawExDM&pid=Api&P=0&w=241&h=161)
- 47. Superficial/ Abaxial sorus: • Receptacle is submarginal in origin on lower surface but the margin of lamina remains active and continues to add new tissue shifting the sorus farther away from margin. • The indusium, if present, is formed from superficial cells of receptacle and overarches it. • In some forms indusium originates from the top of receptacle forming a stalk and a peltate disc. • e.g., Asplenium, Gleichenia, Athyrium, Aspidium (https://live.staticflickr.com/3450/3186416993_1548b1864e_b.jpg, https://wcbotanicalclub.files.wordpress.com/2020/10/asplenium-platyneuron-ebony-spleenwort-sori.jpg?w=1024)
- 50. Phyletic side of a Sorus Marginal position. Migration. Superficial position (https://media.istockphoto.com/photos/sword-fern-spores-on-fronds-picture-id1188490560?k=6&m=1188490560&s=612x612&w=0&h=UJzWwjIwhs3RPldd7PdkgvKQPqPH7vR62GE04YmDqHs=)
- 51. From a tassel to a sorus • Tassel is regarded as primitive and acrostichoid condition as advanced. • Sori are described to be derived from the tassel in three ways: 1. A superficial sorus can be obtained from the tassel by the development of a blade on the axis. This is seen in Osmunda-Todea series. (https://s-media-cache-ak0.pinimg.com/736x/cb/14/d8/cb14d8a20f846677117afa111696e702.jpg)
- 52. 2. A blade with monosporangial sori as in Lygodium can be obtained by a similar expansion as in Osmunda- Todea series but along the axis of sporangial attachment. The solitary sporangia later form sori by increase in number. This can be visualized through Lygodium, Mohria and Gleichenia. 3. The tassels can change into marginal sori by the webbing of sterile stalks of fertile tips. This may be seen in Anemia, Schizaea and Trichomanes series. (https://www.polyploid.net/swplants/images/Lygodium_jap_3Jul07_2008.jpg, https://tse2.mm.bing.net/th?id=OIP.sFvYFbezciRURkzcuYtOtAHaFN&pid=Api&P=0&w=238&h=167, https://www.kaimaibush.co.nz/ferns/Resources/sticheruscunning1.jpeg) https://ww.backyardnature.net/n/10/101226ao.jpg, https://tse3.mm.bing.net/th?id=OIP.4u7OKrkpgPGPu-FhfT8cswHaFk&pid=Api&P=0&w=224&h=168, https://live.staticflickr.com/15/18882865_aeeff55055_z.jpg)
- 53. Protection of a Sorus • Protection of young sporangia during ontogeny is provided by circinate vernation. • The sporangia on expanded sporophyll are with or without the indusium(protective covering). • The sori lacking indusia are exindusiate or naked (Gleicheniaceae). • In forms having marginal sori, the indusium might become a cup or pouch-like structure formed by extension of the abaxial and adaxial margins of leaf (Trichomanes, Davallia, Dicksonia). Dicksonia Davallia Davallia tasmanii Gleichenia (http://www.nzflora.info/factsheet/images/Image1YX8large.jpg ) (https://tse2.mm.bing.net/th?id=OIP.cbF03HezvPVpKPEbFfyO- gDLEy&pid=Api&P=0&w=99&h=148) (https://farm3.staticflickr.com/2483/3899270245_8ca08b372f_z. jpg?zz=1) (http://farm3.staticflickr.com/2644/3938743546_5c0e706374_z.jp g?zz=1)
- 54. • In forms having superficial sori, the indusium is essentially an outgrowth of leaf epidermis. • The indusium is vairable in its form and extent. It may be delicate strip attached along one side only- Unilateral indusium ( Asplenium). Reniform and attached at sinus (Dryopteris). A peltate disc (Polystichum, Cyrtomium) Circular Horse shoe shaped Cup-shaped Dryopteris Asplenium Polystichum (https://delawarewildflow ers.org/images/110911_13 1150.jpg) (http://2.bp.blogspot.com/- x6CBXBX6jtQ/VAsLoiRI0jI/AAAAAAAAbzs/65AMLtVg ycU/s1600/Dryopteris%2Bfilix%2B- mas%2B'Euxinensis'%2B%2Bspores%2B06092014%2 B(4).JPG) (https://tse3.mm .bing.net/th?id= OIP.Co53SMSgjZ H28A- G9GedaQAAAA& pid=Api&P=0&w =255&h=188)
- 55. • Instances where reflexed leaf margin provide protection to sporangia are refered as false indusia. • The indusium in superficial sori can be seen to have undergone a further change. The point of attachment migrated from margin to the centre of receptacle and it became a radially symmetrical structure. • From a radially symmetrical indusium, an elongate lateral indusium is derived by the extension of the area of attachment along on side. This is seen in Aspidium- Athyrium-Asplenium series.
- 56. Maturation of Sporangia within a Sorus Simple Sorus: • A sorus in which all of the sporangia originate, grow and mature at the same time. • Forms showing such conditions are grouped together as 'Simplices' but are not necessarily closely related. • Primitive • Found in ancient fossil ferns Gradate Sorus: • If sporangia develop over a period of time with oldest sporangia in the centre and successively younger sporangia towards the base. • Forms showing it are grouped together as 'Gradate'. Mixed Sorus: • When sorus shows an intermingling of sporangia of different ages it is a mixed sorus. • Condition is termed 'Mixtae'. • More highly specialized and evolved families have this mode of soral development.
- 57. Sporangia in Cladoxylon • Some of the dichotomously branched, fan-shaped leaves were fertile. • Each segment of the sporangiophore terminating in a simple sporangium. • Homosporous.
- 58. Sporangia in Coenopteridales • Eusporangiate. • Usually homosporous but Stauroptreis was heterosporous. • Some had annulus. Sporangia in Stauropteris Large, thick –walled sporangia were borne at the terminus of branches. S. oldhamia from Upper Carboniferous was homosporous, but S. Burntislandica from Lower Carboniferous was heterosporous. Dehiscence was by means of an apical pore. Numerous spores.
- 59. Sporangial & Soral Characters in Angiopteris • Fertile leaves are alike the sterile leaves in form. • Sporangia are borne in distinct sori on the abaxial side of the leaves. • Sori are superficial. • Oblong rings of free sporangia occur, each over a vein. • They are sessile and arise in two rows beneath veins towards the margins of the pinnules. • All the sporangia in a sorus are free from each other. (https://tse3.mm.bing.net/th?id=OIP.otyl4nF0hunGfpOQzpqMAgHaE8&pid=Api&P=0&w=253&h=169) (https://pics.davesgarden.com/pics/2019/07/31/DaylilySLP/cce4f2. jpg)
- 60. • Eusporangiate. • Simple. • Free sporangia have a band of enlarged cells of thicker walls. • Each sporangium has a several layered thick wall, with stomata in the outermost layer. • High spore output: 1450-7000. • No annulus, sporangia open by slits on the inner side, or by pores near the apex. (https://www.fernsoftheworld.com/wp- content/uploads/2014/09/Angiopteris_video.png)
- 61. Sporangial Characters in Ophioglossum • Sporangia are produced in two rows on a fertile spike that arises at the junction of the petiole with the sterile lamina, on its adaxial surface. • Spike is a simple, more or less cylindrical and stalked structure with laterally fused elongate synangia. • Generally, a single spike is associated with a leaf but in O. palmatum several spikes are present on a single leaf. • The fertile spike bears two marginal rows of sunken and laterally fused sporangia. (https://ebps.org.uk/wp-content/uploads/2017/06/DSC05036.jpg) (https://www.delawarewildflowers.org/images/ ophioglossum_vulgatum_2.jpg) (http://1.bp.blogspot.com/_mFm838BFqBE/TS6qICNB31I/AAAAAAAAAcw/flK9jA1UM5c/s1600/ophioglo ssum-esporangios8.jpg) (https://alchetron.com/cdn/ophioglossum- pusillum-cea403e3-ab09-4eea-a08b-3b793f6ddb2- resize-750.jpeg)
- 62. • The apical region of the spike which is somewhat conical and devoid of sporangia projects as a sterile process. • The length of the spike varies according to the species. • Prominent vascular bundle and stomata are present on spike. A ring of bundles become organized within the stalk of the complex. At higher levels, the bundles on the adaxial side become more closely grouped and enter the fertile spike. • The number of sporangia in each spike ranges from 6-20, according to the size of the plant.
- 63. • A number of vascular strands run longitudinally up the middle and from these strands develop the lateral branche s which lead to the sporangia. • At maturity, each sporangium is spherical or oval and remains embedded in tissue of the fertile spike. • The wall of the sporangium is several layers thick. • Stomata are present in the sporangium wall. • Homosporous. (https://tse4.mm.bing.net/th?id=OIP.aTaqWvesNGE9gKvx15F PCAHaFk&pid=Api&P=0&w=236&h=177)
- 64. • Below it, is tapetum that comes from the inner most wall layer. • No special dehiscence mechanism. It takes place by drying out and shrinking of the sterile tissue within the spike. • Each sporangia opens by a transverse slit in the sporangial wall. • Spores as many as 10000. (https://ebps.org.uk/wp-content/uploads/2017/06/DSC05039.jpg)
- 65. Morphological Nature of Spike • Bower (1896) suggested that fertile spike is a single septate sporangium growing on the adaxial face of the leaf. • This interpretation was later on (in 1911) rejected by Bower himself. • According to present considerations, the fertile spike is regarded pinna-like in nature. • It has been held by Goebel (19150, that the spike represents a single pinna. • According to Roeper (1859), the spike represents two basal pinnae whwich have fused laterally, during the ontogeny to form the spike. The interpretation is supported by the course of vascular supply to the spike. The spike exhibits the same vascular supply as would ordinarily go to a pair of pinnae. Later this interpretation was supported by Chryslar (1910) and Bower (1926). • According to Zimmermann (1930), the fertile spike and sterile lamina are the divisions of a leaf, representing a dichotomy. (https://ebps.org.uk/wp-content/uploads/2017/06/DSC05034V2.jpg)
- 66. Soral & Sporangial Characters in Osmunda • Sporangia do not occur in sori and are attached along the margins of non-laminated fertile pinnules, forming tassel-like structures: either on an entire leaf (O. cinnamomea) on part of it ( O. regalis, O. claytoniana) • Sporangia are not protected by indusium. • In O. regalis, the fertile pinnules are found in the distal regions of the leaf. • In O. claytoniana, the fertile pinnae are restricted to the middle of the leaf. • In O. Cinnamomea, there are two kinds of leaves, the sterile and fertile. The fertile leaves are reduced and blade-less. (https://pics.davesgarden.com/pics/2006/06/03/Equilibrium/7cc 035.jpg) (https://tse3.mm.bing.net/th?id=OIP.vaYLvrppt0OiThn9QMZ wrgHaJ4&pid=Api&P=0&w=123&h=164) (https://www.gardenersdream.co.uk/images/osmunda-regalis-p4672-37141_image.jpg)
- 67. • Homosporous • Transitional type of sporangial development. • Lack an indusium. • During the course of sporangium development, the walls of a group of jacket cells located near the tip towards one side of the jacket become thickened to form the rudimentary annulus. • Mature sporangia is a large pyriform body with short and massive stalk. • One-layer thick wall. (https://i2.wp.com/mgnv.org/wp- content/uploads/2021/07/Sporangia_Osmunda_spectabilis_fertile_ leaflets_May_MMF.jpg?resize=1536%2C1398&ssl=1) (https://live.staticflickr.com/6011/5937579433_99ec74f7c5_ b.jpg)
- 68. • Dehiscence of the sporangium takes place by vertical split starting from the rudimentary annulus to the outer side of the sporangium. • High spore output: 128-512. • Spores are spherical with a triradiate mark and abundant chloroplast. (https://live.staticflickr.com/2692/4382051069_eae4 a41938_b.jpg)
- 69. Soral & Sporangial characters in Marsilea • Heterosporous. • Reproductive structures are flattened bean-shaped, spherical to ovoid, epipetiolar, stalked sporocarps, inserted a short distance above the petiole. • Length of the stalk and its point of attachment is variable in different species. • Normally there is one sporocarp per petiole but in forms like M. polycarpa, there are large number of sporocarps attached on one side of petiole and in M. quadrifolia the stalk is occassionally branched forming 2- 3 sporocarps per petiole. (https://3.bp.blogspot.com/-gNPth- RdjmE/WHpYwEldbHI/AAAAAAAAI7I/esevM2uPAZ8ZW14OiyTKMsjVhJkJc_axgCEw/s1600/Marsilea%2Bsporocarp.jpg, https://tse1.explicit.bing.net/th?i d=OIP.4XSzRMex9vqL2wFM8ZpQugAAAA&pid=Api&P=0&w=246&h=152)
- 70. • In some species, the sporocarps have distinct external ridge, the raphe and two bumps. • The raphe represents the end of attachment of the stalk. • One of the bumps is stouter and is present at the end of the raphe. • The sporocarps have a thick wall resistant to injury and dessication and are reported to remain viable up to 35-40 years. The outer layer is epidermis made up of single-layered cuboidal cell with sunken stomata. • Inside the sporocarp, around the cavity extends a ring of gelatinous tissue. • There are rows of elongate sori, on either side, extending transversely to the long axis of the sporocarp. • Each sorus is borne on an elongate receptacle which is attached to the gelatinous ring, at its two ends as well as to the wall of sporocarp on one side, along its length; the other side faces the lumen of sporocarp. • Number of sori in each sporocarp may vary from 2 in M. aegyptiaca to 20 in M. Quadrifolia. (https://www.biophotosharing.com/getphoto.php?id=357) (https://tse3.mm.bing.net/th?id=OIP.2m- NVRkuOdL8zW0MN4H8nwHaGR&pid=Api&P=0&w=215&h=1 82) (https://upload.wikimedia.org/wikipedia/commons/thumb/3 /33/Marsilea_expanded_sporocarp.jpg/1024px- Marsilea_expanded_sporocarp.jpg) (https://tse1.mm.bing.net/th?id=OIP.86lZ6DX0c8d3W7ycTdQ SHwHaFj&pid=Api&P=0&w=221&h=166)
- 71. • Each sorus is enclosed by a delicate diaphragm, the indusium. • On the crest of the receptacle are borne a number of megasporangia each having a single large megaspore. • Along the sides of the receptacle are borne smaller microsporangia each having numerous microspores.
- 72. •The vascular supply to the sporocarp branches from the margin of petiolar trace. From the main trace arise pinnate series of traces, on each side. These lateral bundles alternate with one another. •Each of the lateral bundles bifurcates and the vascular supply to the individual sorus known as placental bundle arises at the point of forking. •The placental bundle in turn bifurcates to form dorsal and ventral traces. •Towards the lower margin of the sporocarp, there is a network of veins due to anastomoses of the pinnate series of bundles.
- 73. • The sporocarps open only in water, splitting bivalve-like. • The process is initiated by the absorption of water by gelatinous ring which expands and frees the sori from the wall of sporocarp by an abscission along the receptacle. This is followed by the breaking of ring at one end. The broken gelatinous ring results into an elongate worm-like structure dragging the sori along with it. • Microspores are small globular cells. • Megaspores are large, ivory- white papillate structures enclosed by gelatinous layer and are visible to naked eyes. https://tse4.mm.bing.net/th?id=OIP.MaVu1a- d_04OPFZsDty6VAAAAA&pid=Api&P=0&w=154&h=154, https://live.staticflickr.com/1383/5120664022_d29d4d5cdf_b.jpg)
- 74. Morphological Nature of Sporocarp • Two manin interpretations: 1. Leaf-segment or laminar hypothesis: Sporocarp is a lateral modified fertile segment of the leaf. 2. Petiolar hypothesis: Sporocarp is homologous with the swollen end of the petiole of a sterile leaf whose marginal cells differentiate into sporangial initials instead of the four leaflets.
- 75. Soral & Sporangial Characters of Salvinia • Sporangia are aggregated into sporocarps. • The sporocarps appear in chains or clusters ranging in number from 4 to 20. • The sporocarps are usually borne on the inner segments of submerged leaves. • In arrangement, the sporocarps are sympodial. • The shape of the sporocarp varies from globose to ovoid, occasionally flattened also with ridged surfaces. • The wall of the sporocarp is made up of two layers of cells. The outermost layer when young is clad with hairs. • Externally all sporocarps are alike. But unlike in Marselia, the sporocarps are mono-sporangiate. (https://tse4.mm.bing.net/th?id=OIP.ZOtkqmEbuAdDKNhn- jqtOAHaHR&pid=Api&P=0&w=164&h=161, https://tse4.mm.bing.net/th?id=OIP.eFvQgx vEaqSC1zvQtz7AEwHaFj&pid=Api&P=0&w=240&h=180)
- 76. • In each sporocarp there is an elevated receptacle bearing sporangia. • The receptacle receives a vascular trace from the leaf segment. • The first one or two sporocarps in each cluster are megasporangiate whereas all the later formed ones are microsporangiate. • In a megasporangiate sporocarp, only about 25 mega- sporangia are seen whereas in a microsporangiate sporocarp, the number is much larger because of the branching of the receptacle. • Leptosporangiate. • Sporangial wall is delicate and single layered, without annulus. • As the spores mature, the tapetal cytoplasm encompassing the spores gets hardened and forms a mass called ‘massula’. • After the sporangia are mature the sporocarps get detached from the leaves and sink to the bottom of the pond. • The sporocarps open up due to the mechanical decay of their walls. This results in the release of spores, which rise to the surface where the rest of life cycle is completed. (https://live.staticflickr.com/7224/7212694442_3f42c67cec_z.jpg, https://pubs.usgs.gov/ds/854/Photograph_collectio n/Plants/Ferns/Salvinia%20molesta_sporocarps_0008.JPG)
- 77. Soral & Sporangial Characters of Azolla • Heterosporous. • Sporocarps are dimorphic: mega- & microsporangiate. • Sporocarps are monosporangiate. • Sporocarp wall is bilayered and delicate except at the tip of megasporangiate sporocarp where it is firm. • Microsporangia are globose, long stalked producing 64 spores. • Megasporangiate sporocarp contains one megasporangium which produces 32 spores, all of which except one degenerates. (https://www.researchgate.net/profile/Yudh-Singh/publication/273169664/figure/fig2/AS:523095527170048@1501727100077/Azolla-microphylla-plants-showing- sporulation_Q640.jpg, https://www.wnmu.edu/academic/nspages/gilaflora/a_mexicana1.jpg)
- 78. • In microsporangium, the tapetal plasmodium develops a number of vacuoles. Each vacuole becomes hardened and divided by partitions into number of alveoli. Each hardened alveolar material within which the microspores are embedded is called a massula. • In some species, the massula develop tubular outgrowths with the anchor shaped tips called glochidia. These structures helps in attaching the microspore massulae to the megaspore massulae. • In megasporangium, tapetal plasmodium divides into 4 massulae. One of thse envelopes the single megaspore. The other three massulae are grouped above the megaspore. (https://tse1.mm.bing.net/th?id=OIP.hC0fIfz9FNTi_qgZO8dyOAHaGq&pid=Api&P=0&w=197&h=177, https://microscopyofn ature.com/sites/default/files/2020-01/Kapsel.png)
- 79. • The presence or absence, and form of glochidia on a massula are important characters, delimiting the species. • The sporangium is covered by a two layered inducium. • Massulae and megaspores are released by the decomposition of sporocarp wall.
- 80. Comparing the sporocarps of Marsilea, Salvinia & Azolla Marsilea Salvinia Azolla • Sporocarp is monomorphic • Monomorphic • Dimorphic • Sporocarp is bisporangiate • Monosporangiate • Monosporangiate • Heterosporous sporangia • Heterosporous sporangia • Heterosporous sporangia • Sporocarp wall is 3 layered. • Bilayered • Bilayered • Thick & resistant wall • Delicate wall, with outer layer covered with hair. • Delicate except at the tip of megasporangiate sporocarp where it is firm. • Normally there is one sporocarp per petiole. • Sporocarps appear in chains or clusters ranging in number from 4 to 20 • Sporocarps are developed in groups of two or four in the axil of the dorsal lobe of the sporophyll. • Massulae absent. • As the spores mature, the tapetal cytoplasm encompassing the spores gets hardened and forms a mass called ‘massula’. • Massula present.
- 81. • Gloichidia absent • Gloichidia absent. • In some species, the massula develop tubular outgrowths with the anchor shaped tips called glochidia. These structures helps in attaching the microspore massulae to the megaspore massulae. • Each sorus is enclosed by a delicate bilayered indusium . • Indusium forms the sporocarp wall. • Bilayered inducium forms the sporocarp wall. • 2-20 sori in each sporocarp. • Single sorus in each sporocarp. • Single sorus in each sporocarp. • Annulus is absent. • Annulus is absent. • Annulus is absent. • Receptacle is branched. • Receptacle in megasporangiate sporocarp is unbranched whereas those in microsporangiate sporocarp is branched. • In a mega-sporocarp, the mega-sporangium arises on a small receptacle at the base. In a micro-sporocarp there is a central cushion like receptacle which gives rise to a number of microsporangia.
- 82. Soral & Sporangial Characters in Pteris • Homosporous. • The sorus of Pteris is called coenosorus . • Coenosori are marginal, borne continuously on a vascular commissure connected with vein ends. • The sporangia of Pteris form a continuous linear sorus along the margin, hence the individuality of sori is lost. • The coenosori are protected by the reflexed margin (false indusium) of the pinnae. • Sori are of mixed type intermingled with many sterile hairs in between the sporangia. • Leptosporangiate type. • A mature sporangium has a long stalk that terminates in a capsule (https://tse3.mm.bing.net/th?id=OIP.7q6bHUIh8LWSMuxIyuF8SAHaFj&pid=Api&P=0&w=217&h=163, https://fernsofmacaronesia.org. uk/wp-content/uploads/2020/06/Pteris-vittata-6-008-1050x700.jpg)
- 83. • The jacket of the capsule is single-layered, but with three different types of cells: (1) A thick walled vertical annulus incompletely overarches the sporangium (2) A thin-walled radially arranged stomium (3) Large parenchymatous cells with undulated walls. • Spores are triangular in shape with trilete aperture, bounded by two walls. The outer wall, exine, is variously ornamented. • The sporangium dehisces transversely along the stomium due to the shrinkage of annular cells. • Each sporangia produces 48 spores.
- 84. Soral & Sporangial Characters in Lygodium • Homosporous. • Sporangia which are produced in abundance are borne in two rows along the ultimate veins. • They form spike like structures on the leaf margin. • A single sporangium occur at the end of veinlet and each is covered by a flap. • The flap is a false indusium representing an extension of leaf margin. • The sporangia are born singly, forming “monosporangial sori” (https://tse2.mm.bing.net/th?id=OIP.b6OAas7gaR7QfY2fMVC1UAHaHa&pid=Api&P=0&w=157&h=157, https://tse2.mm.bing.net/th?id=OIP.7EtS0E8owimX- gjIImlrqgAAAA&pid=Api&P=0&w=192&h=152, https://tse3.mm.bing.net/th?id=OIP.hHJXqpfPnZWZrfb0NNWMagAAAA&pid=Api&P=0&w=230&h=185)
- 85. • Each sporangium has a short and thick stalk with a spore number of 128 –256. • Leptosporangiate development • Massive bilayered tapetum. • The annulus is a terminal group of thick – walled cells, confined to distal end of sporangia. • The dehiscence is longitudinal , most primitive type in ferns. • Capsule of the sporangium is pyriform and curved. • Definite stomium is present and the dehiscence is longitudinal. • Spores are usually triangular, tetrahedral and trilete. • Exine is striate.
- 86. Soral & Sporangial Characters in Acrostichum • The upper pinnae are small and fertile, whereas the lower pinnae are infertile. • The length of the lowest pinna is occasionally smaller than that of the upper pinnae. • Sporangia cover the lower surface of the fertile pinnae or are located at the tip. • The sporangia have many sterile, multicellular filaments that are threadlike, with darkened cells at the end. • This genus gave rise to the word acrostichoid, due to the tightly packed sporangia on the abaxial side of the lamina (Tindale, 2009). • Acrosticoid sorus is the most advanced sorus. https://tse3.mm.bing.net/th?id=OIP.aRs20K90A9nl0_0UEVYjEgHaE8&pid=Api&P=0&w=236&h=157, http://www.discoverlife.org/IM/I_GY /0007/320/Acrostichum_danaeifolium,_sori,I_GY741.jpg, https://tse2.mm.bing.net/th?id=OIP.X61wz3E- gdP2kLo_wDk0nQHaJ4&pid=Api&P=0&w=133&h=178)
- 87. • The presence of sporangia and the absence of sori differentiate Acrostichum fro m other ferns (Hill, 2006). • A mature sporangium has a long stalk that terminates in a capsule. • Exindusiate. • Mixed type of sori. • Spores yellow, tetrahedral, minutely tuberculate or roughene d, equatorial flange absent. • Spores clear to translucent, 1 – 1.5 mm wide, and buoyant. (https://biogeodb.stri.si.edu/bioinformatics/dfmfiles/files/c/25134/25134.jpg)
- 88. Soral & Sporangial Characters in Gleichenia • Sporangia occur in ring-shaped sori on the abaxial surface of the pinnule. • Ex-indusiate. • No segregation of sterile and fertile leaf parts. • Sori are naked and lie in two rows, one on either side of the mid- rib of the pinnule. • Number of sori on a pinnule varies from 1 to many. • Sporangia arise on somewhat elevated circular receptacle and vary in number from 4 to 15. • Size of the sporangia varies with their number within a sorus. • In the species which have few sporangia, the sporangia occur in a uniseriate ring at the margin and the centre of the sorus is vacant. (https://live.staticflickr.com/3450/3186416993_1548b1864e_b.jpg, https://blog.tepapa.govt.nz/wp- content/uploads/2013/02/glechenia_inclusisora_6374_sori_0011.jpg, https://live.staticflickr.com/3810/10328706023_0dc4b4f66a.jpg, http://www.nzflora.info/factsheet/images/Image1YX8large.jpg)
- 89. • In other species, the sporangia found in the centre, lying on top of others. • When examined superficially, a sorus looks like a synangium, but it is not so. • Mature sporangium is pyriform. • Young sporangia are usually covered by hairs or scales. • Sporangia lie on two sides of the midrib of the pinnules. • Some cells of the jacket are thick-walled and form a distinct annulus whose position is oblique horizontal. • Simple sori. • Leptosporangiate development. • Short and stout stalked sporangia. • Distinct annulus present. (https://www.yarraranges.vic.gov.au/files/assets/plants/ferns/605b-2-gleichenia-microphylla-mb.jpg))
- 90. • Single-layered jacket enclosing varying number of spores. • Spore outcome:128-1024. • Each sporangium has a large number of spores and has an obliquely transverse complete annulus which causes longitudinal dehiscence. • Spores are trilete in G. circinata whereas monolete in G. bifidus. • Homosporous. • Has slightly papillate surface. • Spores vary in size according to the species. (http://www.nzflora.info/factsheet/images/Image1YX7large.jpg)
- 91. Soral & Sporangial Characters in Adiantum • There is no distinction into fertile and sterile leaves. • Soru bearing leaves are called sporophylls. • The sori are born superficially at the distal end of the pinnae. But the sori are not exactly marginal. They are borne a little behind the tip of the veins, submarginal. • The sorus bearing margin of the leaf incurls and forms the false inducium. • The sorus is of the mixed type. (https://floracanaria.com/fotos/Adiantaceae/Adiantum_renif orme/image/Adiantum_reniforme_08.jpg) (https://live.staticflickr.com/3477/3809777711_f1bd181c24_b.jpg) (http://1.bp.blogspot.com/- dkVkvx3CJE0/TbCriOkZD1I/AAAAAAAAAyo/4f2RalVdzA4/s1600/hispi dulum-soros.jpg)
- 92. • A mature sporangiuim has a stalk made up of three rows of cells. • The stalk terminates in a globose or biconvex capsule. • The wall is single layered. • The sori are covered and protected by reflexed margins of leaflets, which are membranous structures called false indusium. (https://cdn.auckland.ac.nz/assets/nzplants/Ferns/Some%20Native%20Ferns/Pteridaceae/Adiantum%20cu nninghamii/9-%20adiantum_cunn_lflet5(PS7).jpg)
- 93. • Each sporangium is oblong and consists of a multicellular stalk and the head or capsule. • Capsule is biconvex. • Distinct vertical annulus. • The annulus is separated from the stalk by two or three cells. • The stomium is separated from both the stalk, and the annulus. • The rest of the sporangial wall is composed of a few large cells. • There is an obliquely vertical annulus of 12-24 cells long. • The sporangium dehisces transversely liberating the spores. • Leptosporangiate development. • Homosporous. • Spores are tetrahedral in shape with a triradiate ridge and spore wall is two layered (https://tse4.mm.bing.net/th?id=OIP.ggTtW11L00QFgi9S1AUx2QHaE9&pid=Api&P=0&w=237&h=159)
- 94. Sori in Filicales (https://cdn.auckland.ac.nz/assets/nzplants/Ferns/Some%20Native%20Ferns/Pteridaceae/Adiantum%20formosum/6%20adiantum_form_lflet8(PS7).jpg, https://tse3.mm.bing.net/th?id=OIP.FGouvNmwivn_ftqsTpc0mgHaE6&pid=Api&P=0&w=240&h=159, https://www.polyploid.net/swpl ants/images/Lygodium_jap_3Jul07_2008.jpg, https://live.staticflickr.com/8212/8328709182_961b00354d_b.jpg)
- 95. Reference 1. Yatskievych, George. (2003). Pteridophytes (Ferns). 10.1038/npg.els.0003679. 2. Vashishta, P. C. .Botany For Degree Students Pteridophyta. New Delhi: S. Chand & Company Ltd.,2002. 3. Pandey, S. N, Misra, S. P & Trivedi, P. S. A Textbook of Botany. Thirteenth Edition. Noida, India: Vikas Publishing House Pvt. Ltd.,Vol 2,Part 2, 2016. 4. Rashid, A. An Introduction to Pteridophyta. Second Revised Edition. New Delhi: Vikas Publishing House Pvt. Ltd., 1999.