TRADITIONAL CLASSIFICATION OF GYMNOSPERMS
CLASSIFICATION OF GYMNOSPERMS Classification are merely the opinion of differentauthors gave time from time to time. Classification ofgymnosperm is in topsy turvey state ( disorder,confused or disorganised state). A number ofclassification has been prepared but there is unanimityin them, i e., they all agree about something or all votefor the same thing.
THEOPHARASTUS(370-285 B.C) The term“GYMNOSPERM” wasfirst used byTheophrastus. He wrotea books “HISTORIAPLANTARUM” and“ENQUIRY INTOPLANTS”. In thesebooks he mentioned“GYMNOSPERM” and THEOPHARASTUS“ANGIOSPERM”.
ROBERTBROWN(1827)Further analysis wasmade by RobertBrown in 1827. He forthe first timerecognizedgymnosperms as agroup distinct fromAngiosperms due topresence of nakedovules.ROBERT BROWN
BENTHAM AND HOOKER (1862-83) Bentham and Hooker considered Gymnospermsequivalent to dicotyledonsand monocotyledons .They divided them intothree groups as CYCADACEAEGNETACEAECONIFERAEThey placed them inbetween dicots andmonocots.J. D. HOOKERG. BENTHAM
ADOLF ENGLER (1889) Adolf Engler, after thediscovery of motilesperms in this genus(Hirase 1896), Englercreated a new classGinkgoales for thegenus Ginkgo & itsfossil representatives.ADOLF ENGLER
VAN TIEGHAM(1898)On the basis of Hofmeister work (1851), on thedeveiopment & embryology of diverse plants,Van Tieghem remove gymnosperm from thisintermediate position & place them as one oftwo primary division of spermophyta :1.Gymnosperm (Astigmatic)2. Angiosperm (Stigmatic).Van Tiegham treated Gymnosperms as one ofthe sub-division of Spermatophyta.To accommodate the fossil memberssubsequently three more classes were createdPteridospermaeCordaitalesBennettitalesVAN TIEGHAM
COULTER & CHAMBERLAIN (1910) ENGLER & PRANTL (1926) RENDLE (1926)
COULTER & CHAMBERLAIN(1910) ENGLER &PRANTL(1926) RENDLE(1926) They all considered gymnosperms as a division of Spermatophyta, Phanerogamia or Embryophyta andthey further divided them into seven orders ONIFERALESCORDAITALESGNETALES
A.C. SEWARD(1919)A. C. SEWARD had dividedgymnosperms into two classesClass I- Manoxylic (wood is notcompact due to the presence of welldeveloped pith and cortex and broadmedullary rays.)Orders(i) Cycadales(ii) Cycadeoidales(iii) CycadofilicalesClass II- Pycnoxylic ( wood iscompact as pith and cortex arereduced and medullary rays arenarrow.)Orders(i) Cordaitales(ii) Ginkgoales(iii) Coniferales(iv) GnetalesA.C. SEWARD
BIRBAL SAHNI (1920) Prof. Birbal Sahni, aneminent Indianbotanist, gave for thefirst time a phytogeneticsystem for theclassification ofgymnosperms. On thebasis of themorphological nature ofthe ovule bearing organs,he had given thefollowing classification ofgymnosperms:-BIRBAL SAHNI
GYMNOSPERMSPHYLLOSPERMAE(seeds borne on leaves)Orders Cycadofilicales Cycadales BennettitalesSTACHYOSPERMAE(seeds borne on sSahani did not place Gnetales at anywhere in his classification. Omission of Gnetales wasgreatest draw back of this classification.
GymnospermaeCycadophytaOrders(i) Cycadofilicales(ii) Cycadales(iii) BennettitalesConiferophytaOrders(i) Ginkgoales(ii) Cordaitales(iii) Coniferales(iv) Gnetales
PROF. DIVYA DARSHAN PANT (1919-2001) Prof. D.D. Pant was an excellentteacher as well as a distinguishedvisionary. He was the founder of astrong school of research inpalaeobotany and morphology in theDepartment Of Botany, AllahabadUniversity. He was fully devoted anddedicated to the cause of botany, evenduring his retired life. This can be wellknown by an incident – “He sent anadvance letter to the Vice Chancellorof Allahabad University, he expressedhis wish for not holding any condolencemeeting at his death, so that work isnot hampered”.
D.D. PANT’S CLASSIFICATION OFGYMNOSPERM
CLASSIFICATION BYGIFFORD AND FOSTERGIFFORD
S.V. MEYEN (1986)Division- PinophytaClass- rialesPentoxylalesEphedralesClass- dalesBennettitalesGnetalesWelwitschialesClass- PinopsidaOrdersCordaianthalesPinales
PROF. DIVYA DARSHAN PANT (1919-2001)- Prof. D.D. Pant was an excellent teacher as well as a distinguished visionary. He was the founder of a strong school of research in palaeobotany and morphology in the Department Of Botany, Allahabad University. He was fully devoted and dedica
THE GYMNOSPERMS Seed Plants Gymnosperms Produce Pollen unlike bryophytes & ferns contains male gametophyte dispersed primarily by wind Produce Seeds unlike bryophytes & ferns precursor “contains” the female gametophyte and then the sporophyte embryo Gymnosperms
The Gymnosperms Gymnosperms are simply seed plants that are not angiosperms. This means that they are grouped by what they don’t have. Gymnosperms do not bear fruits and their seeds are not enclosed. ‘Gymnosperm’ literally means naked-seeded as their seeds are not enclosed in fru
GYMNOSPERMS Introduction –Gymnosperm means “naked seed” (From the Greek: gymnos naked; sperm seed) More advanced than ferns –do not have spores, they have seeds. The seeds of the gymnosperms lack a protective enclosure (unlike flowering plants which have flower
2 Gymnosperms Gymnosperms ( naked seed ) are a diverse group of seed plants and are paraphyletic. Paraphyletic groups do not include descendants of a single common ancestor. Gymnosperm characteristics include naked seeds, separate female and male gametes, pollination by wind, and tracheids,
(C) Gnetophyta3 (vessel-containing gymnosperms). (D) Coniferophyta (conifers). Evolutionary Advances of Gymnosperms Gymnosperm is a "catch-all" term for seed plants that do not produce flowers. The first three gro
Gymnosperms A gymnosperm is a vascular plant that produces seeds lacking an outer fruit. Normally these seeds are contained in cones. Gymnosperms have male and female cones. The male cones produce sperm, which are contained in pollen grains. Male cones are normally smaller than femal
Reproduction in Gymnosperms . The majority of gymnosperms have reproductive structures that are known as cone s . The cone is covered with scales for protection and to help secure the cone to the ground. A cone is either a male or female reproductive structure of a gymnos
Gymnosperms of the region also share distribution with adjacent regions especially the coniferous plants. Northeast India has highest diversity of gymnosperms in India. With 24 species, conifers are the most diverse group followed by Gnetales wi
