Selaginella Botany Note

Selaginella systematic position:- Division Lycophyla Clan- Liguro sida Ondere-Selaginellaves Family-Selaginellaccue Genus - selaginella Habit & Herbitat: Dot is found growing many endere shady a damp Pleeves species and herebaceau perceniales & some aree annuals. Moruphology: Liat is commonly called eis clubmoss & the plant body Is a sporcophyte. (2) The sporcu Phyte is evergreen, creeping, hereb with & Leaf breamching &ifferrentiated into root, stem (3) The Mem is cylindicical with rises & ferrerrows ? is dichotomously biranched (4) The stem beares y cows of small leaf, out of 4 rows 2 cows arre smallere than the othere 2. (5) The leaves are heterophyllous, foliose Leaf & Sporcophylls. The porrophylls are developed at the terminal paret of breanches in the forem of Strobikus. (6) Foliose Leaves arce roughly trclangulare & painted Whien containa a legum at their bowe At the place of dichotomi, some times. Leafless elongated breanch arise from the lowerisite called rchizophore with chizoids. Anatomy of Hem; The fos Tis of stem shoως Following Aru 1. The epidermis is single layere & parenchymalow with no tomata. 2. Cortex is parenchymatous the epidermis. & present below 3. Neant to corcten a large ceir space is present in the centre of Which the stere is present & suspended by trabeculae. The trabeculae are modified endoderemis. & consists of carparrian stripe... 4. Stere ore vascular Region: (In The Aere is prototellic in naturre olgt consists of a thin walled single layere cell called perciggle, which encircles were. 3) Neat po to pericycle Is phloem & in the centire nytem is present. The xylem is exarech. (4) The protostele is monowell ic in Hem but. In the uppere region of the axi's stare chaped actinoctele is present. (5) poly stellic condition may be found in many Species. many Anatomy of Root: The root is very simple & hay outere piliferious layere with root haires (2) Below. Piliferous layere schlercenchymatous hypoderem present. (3) The hypoderemis is followed by parenchymatous Corten below which endoderem & perciègere present. (4) The Here is protostellic in nature. Anatomy of Hem; The fos Tis of stem shoως Following Aru 1. The epidermis is single layere & parenchymalow with no tomata. 2. Cortex is parenchymatous the epidermis. & present below 3. Neant to corcten a large ceir space is present in the centre of Which the stere is present & suspended by trabeculae. The trabeculae are modified endoderemis. & consists of carparrian stripe... 4. Stere ore vascular Region: (In The Aere is prototellic in naturre olgt consists of a thin walled single layere cell called perciggle, which encircles were. 3) Neat po to pericycle Is phloem & in the centire nytem is present. The xylem is exarech. (4) The protostele is monowell ic in Hem but. In the uppere region of the axi's stare chaped actinoctele is present. (5) poly stellic condition may be found in many Species. many Anatomy of Root: The root is very simple & hay outere piliferious layere with root haires (2) Below. Piliferous layere schlercenchymatous hypoderem present. (3) The hypoderemis is followed by parenchymatous Corten below which endoderem & perciègere present. (4) The Here is protostellic in nature. (3) Next to tapetam the micrcos porce mother cell are present. These underigo melosis & form many micrcorporre tetrads Development: (1) The development of both micro & mega sporcangia are similare up to differcentiection 2 is eusporcangiate type. of mothere in (2) The sporcangtum originate from sporangium inition whien divides from sporcangial initial, (3) This initial divides by percilinay wall & fopen preimarey jacket cen & primarey acche sporcion cell- (4) The wall cell ore 2 anticlinally Jacket cen to forem divides perciclinally 2 Layered jacket wall! (5) The arche sporian call divides to forem CONS. re outermost tapetam is formed. layere orem sporengenous of this cell the (6) The sporcogenous divides Forms repeatedly & forem cell Sporre mothere cell, up to this stage the development of micro & mega sporeangia is Similare. (7) on microsparrangia all the microsporre mothere cell are Functional cinderego melosis to0 forem tetrahedreal tetrads of microгpоrеs, (8) The maturce microsporcangiem split & the semigerminated microspores falls mega Megasporangio porcangia: (1) It is u lobed, shoretly steuked, has a 2 layerred wall & a thired tapetem (2) out of all megasporee muthere cers only one is fanctonau 2 divides by meiosis to forem 4 haploid mega eporce.. (3) At maturcity the megasporre separate. Deve Lopment- (1) The development is simileere to the microsporangium 121gn mega sporcangium only only one megprporce mother all uthern bute cell rremain functional Idegenercate. (3) The meganporce mothere cell due to melasis produces 4 haploid megasportes (4) The megan megasporces nated condition. arre disseminated in semigermi- Gametophytic Genercaution: (1) Due to heterosporious condition the! micreosporres & meganporres are produced in different sporcophylus. (2) The microsporce produce in moue, gametophyte the megaspore produce in female gametophyte. male gametophyte & Germination of (1) The microsporres are uninucleate haploid Stre: having 31 exime outers en 2 inner entime. (2) The miccubupornces are firest divide into acens upper prothoulicar cell & anthera dial cell. (8) The antheridion cen androgonian divide foreming cell surrounded forenting by u cenfrrou 8 jalket cell. (4) Then the andirogonicu cell divided to forem Larege a redivided no. of antherco zoid Femoue Gametophyte & Germination of me ga sporce (1) The megasporre is the firest stage of Female gametophyle & germinate into female Preothallus. (2)gn the course of development the protoplasm contract to forem the small see like stre. (3) The outere wall of megasporre burest, the nega pore nudes divide preeducing many nuclei which is separeated by foremarton. (4) A Arcirradiate multicelulare preothalles is forum. The gametophyte has opere cushion of small cells & lowere nutcitive zone. (5) At this stage the Released mega female gametophyte is Ichizon shocy develops (6) few may develops from the prie thallus. oregein arcehegonia are The female sean oregein developed from superfician initiarcent (7) The initicus divides by periclinau wall to forem uppere primary Centreal cell. COVERT (8) The centreal cell divides feere there by perciclinay division te forem primarry preimary ventricu cell canoucet 2 93 (9). The preimarty as single Cancu cell does not divided 2 act neek canou cell. The prelmarcy. ventricle cell cell 2 divides & forem ventricu cayou egg cell. (10) The mature archegonium has neek with y Hows of cells. The neck hay one neek canal cell coll The ventere has single, ventreal canal 2 one egg. The neek canal cell Ventreal canal cell disintegrates Fertilization:- 69 The spermatozoid reach the arcchegonien neek 2 fuses with egg oo sporre. to forem diploid zygote ore Embreyo: (1) The zygote is the primary stre. of sporcophytic genereation. The corporre develops into an embryo by ferethere division. (2) The firest division is treamsverse a form upperz Suspensor cells & lowere embryonardell. (3) The embryonal cens produce the embryo. The Suspensore cell forem suspensore.. (4) The embryoncu resulting Cell result cell divides by 2 equan vercticas a quadrecant stage, one of the 4 cells divide by oblique wall Apicou Cels. forming shout (5) The remaining cells divide by transverse wall to forem & cells) in 2 tiere of y cells each. The cells in both tires divide of cellg. & redivide forming a mars (6) Then foot 1 cotyledon from the embryo I stem, & called Legel arce developed Young sporcophyte young sporophyte developed young uem (7) Then the you to cotyledon & a primary rout & becomes independent sporcophyte