Prepared by Dr Thirunahari Ugandhar

1. GYMNOSPERMS
MORPHOLOGY, ANATOMYAND
REPRODUCTIVE STRUCTURE

2. INTRODUCTION
 The Gymnosperms are a group of seed-producing plants that
includes conifers, cycads, Ginkgo, and gnetophytes.
 The term "gymnosperm" comes from word gymnospermos,
meaning "naked seeds", after the unenclosed condition of their
seeds (called ovules in their unfertilized state).
 Gymnosperm seeds develop generally on the surface of scale- or
leaf-like appendages of cones.
 జిమ్నోస్పెర్మ్లు విత్తనాలు ఉత్ెత్తత చేస్ే మొక్కల సమూహం, ఇవి కోనిఫపర్మ్
ు ,
స్పైకాడ్ల
ు , జింగో, మరియు గెనెట్ైైటు ను క్లిగి ఉంటాయి.
 పదం "జిమ్నోస్పెర్మ్" పదం జిమ్నోస్పెరో్స్ నుండి వచ్చంది, దీని అర్మధం
"నగ్ో విత్తనాలు", వారి గింజల యొక్క ఎడ్తెగ్ని స్థిత్తలో (వారి పరాధీన
స్థిత్తలో ovules అని పథలుస్ా
త ర్మ్) త్ర్మ్వాత్.
 జిమ్నోస్పెర్మ్ విత్తనాలు కొలత్ యొక్క ఉపరిత్లంపపై స్ాధార్మణంగా అభివృదిధ
చెందుతాయి- లేదా శంఖుల వంటి ఆక్ు వంటివి.

3. Diversity and Origin
 There are between 700 and 900 extant* or currently living species of
Gymnosperms.
 It is widely accepted that the gymnosperms originated in the late
Carboniferous Period. Early characteristics of seed plants were evident in
fossil progymnosperms of the late Devonian period around 380 million years
ago.
 Extant is a term commonly used in biology to refer to taxa (such as species,
genera or families) that are still in existence (living). The term extant
contrasts with extinct.
 700 మరియు 900 మనుగ్డ్లో * లేదా జిమ్నోస్పెర్మ్్ యొక్క పరసు
త త్ జాత్ులు ఉనాోయి.
జిమ్నోస్పెర్మ్లు చ్వరి కారబొనిఫపర్మస్ కాలం నుంచ్ పుటట
ు కొచాచయని విసతృత్ంగా అంగీక్రించార్మ్.
380 మిలియన్ సంవత్సరాల కరిత్ం సుమార్మ్ చ్వరి దేవొనియన్ కాలపు శిలాజ
ప్రర జిమ్నోస్పెర్మలులో విత్తన మొక్కల ప్ా
ర ర్మంభ లక్షణాలు సెష్ుంగా క్నిపథసు
త నాోయి. * ఉనికరలో
ఉనో జీవనశైలిని సూచ్సు
త నో జీవజాత్తలో (స్ాధార్మణంగా జాత్ులు, జాత్త లేదా క్ుటటంబాలు)
సూచ్ంచడానికర స్ాధార్మణంగా ఉపయోగించే పదం. ఈ పదానిో మనుగ్డ్లో వయతాయసం క్లిగి
ఉంది

5. Diversity and Origin
 Conifers are by far the most abundant extant group of
gymnosperms with six to eight families, with a total of 65- 70
genera and 600-630 species (696 accepted names).
 Conifers are woody plants and most are evergreens.
 The leaves of many conifers are long, thin and needle-like with a
waxy coating, others species, including most Cupressaceae and
some Podocarpaceae, have flat, triangular scale-like leaves.
 Cycads are the next most abundant group of gymnosperms, with
about 130 species. The other extant groups are the 75 - 80
species of Gnetales and one species of Ginkgo.

6. • 60-70 జాతి మరియు 600-630 జాతులు (696 ఆమోదించబడిన
పేర్ల
ు ) మొత్
త ిం ఆర్ల నిండి ఎనిమిద కుటింబాలు కలిగిన
జిమోోస్పెర్లలు చాలా ఎకుువగా ఉన్నోయి.
• కోనిఫర్ల
ు అడవులు మరియు చాలా సత్త్హరితాలతో ఉింటాయి.
అనేక కోనిఫెర్
ు ఆకుల పొడవాటి, సనోని మరియు సూద వింటిద ఒక
మ
ై నపు పూత్తో, చాలామింద కాప్ర
ె స్సీయే మరియు కొనిో
పోడోకార్పెస్సతో సహా ఇత్ర్ జాతులు ఫ్ల
ు ట్, తి
ి భుజాకార్-స్థ
ా యి
ఆకులు కలిగి ఉింటాయి.
• 130 ర్కాల జాతులు కలిగిన జిమోోస్పెర్ల్ యొకు త్దుపరి
అత్యింత్ విస్థ
త ర్మ
ై న బ ిందిం స్ప
ై కాడ్ల
ు . ఇత్ర్ మనగడలో ఉనో
గ్ర
ూ పులు 75 - 80 జాతి జీటాలేలీ్ మరియు జిింగో యొకు ఒక
జాతి.

8. Characteristics of Gymnosperms
 There exist a set of standard feature or characteristics that help
to identify gymnosperms. Here are some of the peculiar
characteristics of gymnosperms
 Gymnosperms do not have an outer-covering or shell around
their seeds.
 Gymnosperms are heterosporous which means that they produce
different male and female spores. The microspores develop into
pollen grains and the megaspores are in an ovule.
 ప్ా
ర మాణిక్ లక్షణం లేదా జిమ్నోస్పెర్మలును గ్ురితంచడానికర సహాయపడే లక్షణాల
సమిత్త ఉనికరలో ఉంది. జిమ్నోస్పెర్మ్ యొక్క విచ్త్ర లక్షణాలు కొనిో ఇక్కడ్
ఉనాోయి జిమ్నోస్పెర్మ్లు వారి విత్తనాల చుటట
ు బయటి-క్వరింగ్ లేదా షపల్
లేదు. జిమ్నోస్పెర్మ్లు హేట్రోస్ర ెరోస్, అంటే అవి వివిధ మగ్ మరియు ఆడ్
స్ర ెర్ము్ును ఉత్ెత్తత చేస్ా
త యి. మైకోిస్ప ెర్మలు పుప్ప ెడి గింజలుగా అభివృదిధ
చెందుతాయి మరియు మగాస్ర ెర్మస ఒక్ అండాకార్మంలో ఉంటాయి.

9. Characteristics of Gymnosperms
 Gymnosperms produce cones.
 Gymnosperms do not bear fruits.
 Gymnosperms propagate via wind pollination.
 The adult plant body is a sporophyte. It is represented by a
perennial, evergreen, woody plant. Most of them are trees
and some are shrubs. There are no herbs.
 Pinus as well as other conifers are evergreen trees. They
have monopodial growth represented by one main axis. As
the axis grows taller it increases in diameter due to
secondary growth. Stem branches are of two types:
1. Long shoots or branches of unlimited growth.
2. Dwarf shoots or branches of limited growth

10. Sporophyte: The asexual and usually diploid phase,
producing spores from which the gametophyte arise.
Monoxylic: Wood is not compact due to the presence of
well – developed pith and cortex and broad medullary
rays.
Pycnoxylic: Wood is compact as pith and cortex are
reduced and medullary rays are narrow.
Sporophylls: Sporangia are formed on specialised
leaves, known as sporophylls.

11. CYCADALES: CYCAS
 The members of this order are commonly known as cycads.
They originated from the seed ferns. i.e., Cycadofilicales,
towards the end of Carboniferous periods and formed a
dominant vegetation during the Triassic periods of Mesozoic
era.
 The order includes eleven living genera and about 100
species. They are usually woody trees except Zamia
pygmaea.
 The stem is mostly unbranched and is covered by persistent
leaf bases. The leaves are arranged in whorls at the apex of
the stem ; they are pinnately compound.
 The wood is monoxylic. The micro-and megasporophylls
usually from male and female strobili.

12. CYCAS
Systematic Position
Division -
Class -
Order -
Family-
Cycadophyta
Cycadopsida
Cycadales
Cycadaceae
 Cycas is the most widely distributed genus of
the order Cycadales. There are about 20
species which occurs in wild state in China,
Japan, Australia, Africa, Burma andIndia.
 Four species of Cycas – C. circinalis , C.
pectinata, C. rumphii and C. beddomei –
occurs in natural state in India, Chiefly in
Assam, Orissa, Meghalya, Andaman and
Nicobar Islands, karnataka and Tamil Nadu.
C. revoluta and C. siamensis are widely
grown in gardens.

13.  Cycas pectinata: It is mainly distributed in Nepal, Sikkim,
hills in Bihar Assam and Chittagong. The plant is 2- 3.5m in
height with a crown of leaves at the top of the unbranched
stem. The leaves are 1.5 – 2 m long with flat and linear
leaflets. The male cones are cylindric- ovoid and about 40
cm long. Each megasporophyll has 4-6 ovules.
 C. revoluta: It is a native of China and Southern Japan and
is widely cultivated as an ornamental plant in India. The
plant is 1.5- 2 m in height and has revolute leaflets. The
male cones are cylindrical or ovoid- oblong. The tomentose
megasporophyll bears 2- 4 ovules.

14.  C. beddomei: It occurs in wild state in Cuddapah district
of Andhra Pradesh. It has a dwarf trunk, only up to 40 cm
high, and strongly revolute leaflets. The rachis is without
spines, but the basal part of the rachis is covered with
tufted hairs. The male cones are oblong- ovoid, and the
megasporophylls are ovate- lanceolate with linear teeth.
 C. circinalis: It is common in the western parts of
Peninsular India, Western Ghats and Orissa hills. It is 1.5-
3 m in height. The leaf has more than 160 pairs of flat and
acuminate leaflets. The male cones are cylindric- ovoid
and the tomentose megasporophyll bears up to 12 ovules.

15.  C. rumphii: This species occurs in Andaman and Nicobar
Islands. The plant is 1.5- 4 m high with 1-2 m long leaves,
each with 50-100 pairs of leaflets. The male cones are
ellipsoidal and stalked, and the megasporophyll is linear-
ovate and 6-10 ovulate.
 C. siamensis: it is widely distributed in Burma, China,
Thailand and Yunnan. In India, It is grown as an ornamental
plant. The plant is about 3 m tall with nearly a meter long
leaves. The male cones are ovoid- oblong, and the
megasporophyll has two ovules.

16. SPOROPHYTE
 Plants are low and palm-like , height 4-8 feet.
 Tallest species, C. media – up to 20 feet high
 Stem unbranched , columnar and covered with persistent
leaf bases.
 Leaf segment remains circinnately involute within the bud–
leaves dimorphic.
 Female reproductive structures–the megasporophylls are
not aggregated in cones.
 Ovules (2 or more) borne on the lower margins in
ascending order

17. External Morphology
Stem- Cycas plant shows tuberous stem when
young , becoming columnar and unbranched
later.
Leaf– Shoot apex is protected by a rosette of
brown scale leaves.
Plant grows very slowly adding a new crown
of leaves every 1 or 2 years , alternating with
crown of scale leaves.

19. External Morphology
The pinnately compound megaphyllous
leaves have 80-100 pairs of leaflets arranged
on the rachis
Leaf base is rhomboidal in shape and
attaches the leaf transversely to the stem
The leaflets are thick , leathery in texture,
ovate or lanceolate in shape & photosynthetic
in function.

20. External Morphology
 Scale leaves are very small , rough and dry , triangular in
shape and brown in colour , thickly coated.
 Root is of two types – normal and coralloid.
 Normal tap-roots grow from the radicle deep inside the
soil giving out lateral branches
 Some of the lateral roots grow apogeotropically towards
the surface of soil and branch dichotomously
 These roots are short , thick and swollen at the tips.

22. External Morphology
 The much branched mass appears like a coral on the soil
surface hence called coralloid roots
 Do not bear root caps
 The cluster has lenticel like apertures
 Become infested by N2
(cyanobacteria); bacteria
fixed blue-green
& diatomse
algae
eg.
Nostocpunctiforme,Anabaenacycadacaerum
 Symbiotic relationship thus established

23. Anatomy
Root
 Young root shows typical structure like that
of a dicotyledonous root
 Outer most layer , epiblema , encloses the
parenchymatous cortex interspersed with
tannin cells and mucilage canals
 Endodermis with casparian thickenings
 Pericycle is multilayered with thin cell
shaving starch grains
 Vascular tissue within is typically radial
 Roots usually diarch to tetraarch , rarely
polyarch
 Vessels absent in vascular tissue
 Pith reduced or absent

24. Anatomy –Root
 Older roots show secondary growth
 Cambial ring is initiated between xylem & phloem and
completed by differentiation in inner layer of pericycle
adjacent to protoxylem elements
 These cambial cells are meristematic and add secondary
xylem on the inside and secondary phloem towards cortex
 Along side phellogen (cork cambuim) develops in outer
most layer of cortex below the epidermis
 This produces dead cork cells (phellem) towards outer
side and living secondary cortex cells (phelloderm) on the
inside.
 Lenticels are developed in old roots

25. Anatomy –Root
Coralloid Roots
Has additional algal
zone in the cortex
Cells of algal zone
palisade like and form
the middle cortex

26. Anatomy –Stem
Stem
 Show irregular outline due to the
presence of leaf bases , therefore
epidermis is not a continuous layer
 Broad cortex is traversed by simple
and girdle leaf traces
 Numerous mucilage canals, starch
grains also present
vascular tissue
 Narrow zone of
having open, endarch vascular
bundles arranged in a ring and
separated from each other by wide
medullary rays
 Pith is large, parenchymatous
shaving mucilage canals and starch
grains

27. Anatomy –Stem
and wide
 Old stem of Cycas shows secondary growth
 Wood manoxylic type with scanty xylem
medullary rays

28. Anatomy –Rachis
Rachis of Cycas
Woody and thick
Hypodermis sclerenchymatous
Characteristic feature is omega
shaped (Ω) outline of the
numerous vascular bundles
Each bundle has sclerenchymatous
bundle sheath and is open ,
collateral.

29. Anatomy –Leaflet
Cycas Leaflet
 Leaflet is thickly cutinized and leathery
 Possesses all xerophytic characters
 Sunken stomata and thickened hypodermis present
 Well developed palisade layer in mesophyll
 Between the palisade and lower mesophyll layers , there are
transversely running long colourless cells in 3-4 layers extending
from mid- rib to near leaf margin
 These constitute the transfusion tissue
 Mid-rib bundle consists of abroad triangular centripetal xylem
and two small patches of centrifugal xylem–thus dipoxylic
 Phloem abaxially placed

30. T.S of Cycas Leaflets

31. Reproduction –Vegetative
 V
egetative reproduction is
by means of bulbils
 Develop in crevices of scale
leaves and leaf bases at the
basal part of an old stem
 Produces new plant on
detachment

32. Reproduction –Sexual
 Strictly dioecious plant
 Male plants are rare
 Male strobilus or cone borne singly at the
apex of the trunk
 Apical shoot apex utilized in the
development of male cone, hence branching
sympodial
 Cone shortly stalked & large (upto 50 cm
length or more)
 Numerous micro- sporophylls spirally
arranged around the central axis
 Each micro- sporophyll is narrow below
and broad above terminating into
projection–the apoplysis
 Microsporangia confined to abaxial (lower)
surface
 Usually present in sori– each with 2- 6
sporangia
 They contain a large number of haploid
microspores (pollen grains)
STROBILUS

34. Female Reproductive Structures
 Female plant do not produce
definite cones
 A whorl of spirally arranged
megasporophylls arise around the
shortapex
 Each megasporophyll resembles
thefoliageleafandapproximately
10-23cms.long
 Lower petiolar part bears the
naked ovules on the margins

35. Ovule Structure
 Largest ovule (6 cms. X 4
cms.) seen in C. circinalis
 Ovules are orthotropous,
sessile , ovoid or spherical in
shape and unitegmic.
 The thick integument is
differentiated in three layers-
outer and inner fleshy layers ,
middle stony.
 The integument remains fused
in side with nucellar tissue
except at the position where it
forms the micropylar opening.
 Ovule is well supplied with
vascular bundles.

36. Megasporangium
The megaspore develops in the nucellus by
meiotic division and goes on to form female
gametophyte tissue.
2- 3 archegonia are formed in this haploid
tissue which is food laden.
Egg cell in the venter
undergoes fertilization
of archegonia ,
by the motile
spermatozoid forming diploid zygote.

37. Pollination -Development of male
gametophyte after pollination
 The pollen grains are carried by wind
(Anemophily) and caught by pollination
drop secreted by ovule. Pollination is direct.
 The pollination drop is dehydrated and the
pollen grains are sucked in to the pollen
chamber.
 Pollen grains take rest for sometime in the
pollen chamber.

39.  During the germination of pollen grain the exine is ruptured and the
inner intine comes out in the form a tube like structure known as
pollen tube.
 At this time the generative cell divides and forms a larger, upper
body cell and smaller , lower stalk cell.
 The pollen tube acts as haustorium to absorb food materials from the
nucellus besides as sperm carrier.
 The body cell divides and forms two naked , top shaped , motile ,
multiciliated antherozoids. The cilia are in 4–5 spirals.
 The male gametes of Cycas are 180–210 μ in size and largest in the
plant kingdom.
 The pollen tube apex is ruptured and the male gametes are released
into the archegonial chamber.
 Presence of multiciliated male gametes is the fern character shown
by Cycas male gametophyte

40. Young Sporophyte–Embryo
Embryo development is meroblastic.
Pro embryo shows upper haustorial
part, middle elongating suspensors and
the basal meristematic embryonal
region.

41. LIFE CYCLE OF GYMNOSPERMS

42. CONIFEROPHYTA: PINUS
 This is the largest division of gymnosperms, which includes
Pines, Yews, Spruces, Junipers, Cedars and many more
plants
 With approximately 588 living species, this is the most
diverse and by far the most ecologically and economically
important gymnosperm group
 They are usually long, branched and evergreen trees. The
branches usually dimorphic and bear needle like, linear or
lanceolate leaves.
 The wood is pycnoxylic, characterised by the presence of
resin canals.
 The micro and megasporophylls form compact cones. The
male gametes are non- motile and the fertilization is
siphonogamous.

43. PINUS
Systematic Position
Division - Coniferophyta
Class- Coniferopsida
Order- Coniferales
Family- Pinaceae
Genus- Pinus
 Pinus is one of the most important taxon of the order conoiferals,
is represented by about 105 species, distributed throughout the
northern hemisphere.
 Five species of Pinus occurs in the Indian sub continent of these
four species are confined to the north east and north west
Himalayan regions.

44. 1. Pinus roxburghii: Pinus roxburghii (known as chir pine) is a
species of pine. Pinus roxburghii is a large tree reaching 30–
50 m (98–164 ft) with a trunk diameter of up to 2 m (6.6 ft),
exceptionally 3 m (10 ft). The bark is red-brown, thick and
deeply fissured at the base of the trunk, thinner and flaky in
the upper crown. The leaves are needle-like, in fascicles of
three, very slender, 20–35 cm (7.9–13.8 in) long, and
distinctly yellowish green.
2. Pinus wallichiana: The leaves ("needles") are in fascicles
(bundles) of five and are 12–18 cm long. They are noted for
being flexible along their length, and often droop gracefully.
The cones are long and slender, 16–32 cm, yellow-buff when
mature, with thin scales; the seeds are 5–6 mm long with a
20–30 mm wing.

45. 3. Pinus gerardiana: This species common in Kashmir and
Kinnaur district. The trees are 10-20 m tall with usually deep,
wide and open crowns with long, erect branches. However,
crowns are narrower and shallower in dense forests. The
leaves are needle-like, in fascicles of 3, 6–10 cm long,
spreading stiffly, glossy green on the outer surface, with blue-
green stomatal lines on the inner face; the sheaths falling in
the first year.
4. Pinus merkusii: This species occurs on the hillock in East
Bengal at an altitude of 150- 600 meter . The plant is only 3-4
meters high. There are two needles in each foliar spur.

46. 5. Pinus insularis: This species is widely distributed in
khasya regions of Assam at an altitude of 700- 1850
meters. The plant attain a height of about 30 meters and
the foliar spurs are trifoliate.

47. Sporophytic Plant Body
Adult plants are tall trees up to 200 feet in height
Perennial, xerophytic plants appearing pyramidal or
conical due to radial branching
Branches are dimorphic – long shoots and dwarf
shoots (spurs)
Leaves are dimorphic – Scale leaves and green
acicular leaves
Male and female cones present on the same plant,
hence monoecious

48. External Morphology – Stem
Erect, tall, cylindrical,
woody and branched
Branching monopodial
and excurrent
Lower branches longer
and horizontal giving
the conical shape to the
plant

49. Branches of unlimited growth are the long shoots
Arranged spirally around the main trunk
Bear scale leaves and dwarf shoots in axils of scale
leaves
Branches of limited growth or dwarf shoot lacks
apical bud
Possess 8-10 spirally arranged scale leaves
terminating into 1-5 needle like foliage leaves at apex

50. External Morphology – Leaves
 Scale leaves thin, brown and small
 Main function is to protect young
buds & conserve water around the
branches
 Foliage leaves are long & acicular
(needle like)
 Remains green for a number of
years (3-10 yrs) hence plants are
evergreen
 No. of needles per spur varies from
1-5 with species (monofoliar to
pentafoliar)

51. External Morphology – Root
Plant possesses tap root
Elongated structure with strong lateral branches
Root-hairs scanty; function taken up by ectotrophic
mycorrhiza (fungus roots)
It is symbiotic association of fungal mycelium on the
root’s surface
Helps in absorption of nutrients & protection from
pathogens
Fungal species identified are Rhizopogon, Amanita,
Boletus, Entoloma, etc. – mostly members of
Basidiomycetes

52. Anatomy – Root
 Resembles typical dicotyledonous
root.
 Pili ferous epiblema bear unicellular
root hair (seen only in young roots)
parenchymatous cortex
and pericycle layers
 Broad
follows
 Endodermis
seen next
 V
ascular tissue is radially arranged
in 2-6 groups of xylem and phloem
 This tissue lacks true vessels and
companion cells
 Resin canals present in xylem patch
making it Y-shaped
 Old roots show secondary growth

53. Anatomy – Stem
 Typically dicotyledonous stem
 Cuticularized epidermis encloses the
lignified sclerechymatous
hypodermallayerbelow
 Inner cortex is thin walled
parenchyma containing chloroplasts
and resincanals
 Vascular bundles are conjoint,
collateral, endarch , open and
form a ring
 Medullary rays are narrow
 Vessels in xylem and companion
cellsinphloemareabsent

54. Secondary growth in stem
 Ring of vascular cambium develops
 Remains active each year forming
spring wood & autumn wood – annual
rings
 Important in dendrology for estimation
of the age of the plant
 Secondary medullary rays usually
uniseriate
 Pinus wood is dense and massive with
few parenchyma cells – pycnoxylic
 Cork cambium (phellogen) formed in
outer cortical layer
 Forms secondary cortical cells
(phelloderm) towards inner side and
cork (phellem) on outer side

55. Anatomy – Leaf
Xeromorphic
P
. longifolia is trifoliar; so the
needle shows triangular
outline
Outermost epidermal layer
has thick-walled cells
which are cuticularized
Stomata are sunken
Hypodermisissclerenchymatous

56. Mesophyll not differentiated further
These cells have peg-like in foldings of cellulose
projecting in their cavities
Have a large number of chloroplasts & starch grains
Resin canals with secretory tissue present
Two vascular bundles with conjoint
tissue present in the middle

57. REPRODUCTION
Takes place by means of spores –
microspores (male) and
(female). The plants are
megaspores
therefore
heterosporous
The male and female cones occur on the
same plant, but different branches i.e.
monoecious

58. Male cones (Staminate cones)
 Borne on the lower branches in the axils of scale leaves.
 Appear in the month of January (in plains) and March (in
hills) reaching maturity within 2-3 months.
 Can be seen in clusters just behind the shoot – apex.

59. Male cones (Staminate cones)
Each cone has 60-100 spirally arranged
microsporophylls
Two microsporangia are present on the
underside of each microsporophyll
Development of microsporangium is
eusporangiatetype
Within the microsporangium, the microspore
mother cells undergo meiotic divisions to
form haploid microspores

60. Microspore (Pollen grain)
 It is surrounded by a 3-layered wall
 Exine heavily cuticularized on one side
of the microspore
 Middle layer (exo-intine) projected
outwards into two large balloon-like
air sacs or wings
 Inner layer (intine) is very thin
 On maturation the spores germinate in
situ. Hence, early gametophytic
development is precocious
 At the time of dehiscence, huge
quantities of microspores form yellow
clouds around the pine forests. It’s
called the “Shower of sulphur dust”

61. Female cone (Ovulate cone)
 Borne on the upper branches of the tree, in axils of scale leaves
either singly or in groups of 2-4.
 Female cones are seen in February and get pollinated within 3-4
months
 Complete maturation and seed dispersal takes place in the 3rd
year of development
 Each cone consists of central axis bearing spirally arranged
ovuliferous scales (60-70)
 On young cones a small thin & leathery bract scale can be
below the ovuliferous scale
 Each ovuliferous scale has two ovules on its upper surface
 Cone on maturity is usually cylindrical and 15-20cms in length

62. Female Cone

63. Megasporophyll
The ovuliferous scale is thick, large, woody
& brownish structure
More or less triangular in outline – broad,
terminal portion is apophysis with its
centrally projected area – the umbo
Basal portion is narrow and bears two naked,
sessile anatropous ovules on its upper surface

64. Ovule Structure
 Micropyle of the ovule faces the central axis of the cone
 The single integument is fused to the nucleus except for
a short distance near the micropyle
 Embedded in the nucellus ,the archesporial cell divides
meiotically to form four megaspores

65. Male Gametophyte
 Early development takes place inside the microsporangium
 Pollen grains are released at the 4- celled stage (2 prothalial,
a generative cell and tube cell )
 Pollination is anemophilous and pollen reach the pollen
chamber of the ovule through micropyle
 Further development here, results in the formation of pollen
tube which carries the two unequal male gametes to the
neck of the archegonium
 The released male gametes will fertilize the egg cell
resulting in zygote formation
 Time gap of 12-14 months is seen between pollination and
fertilization

66. Female Gametophyte
The inner most functional megaspore
further gives rise to the haploid female
gametophyte tissue wherein the archegonia
develop.
The venter of the archegonia contains the
upper ventral canal cell and the larger egg
cell.

68. Young Sporophyte
Embryo development is meroblastic
In early stages the embryonal tier of the pre-
embryo splits apart forming 4 apical segments
each with its suspensor
Each of these terminal embryonal cell give rise to a
mature embryo , thus Cleavage polyembryony is
observed

71. Gymnosperms-general charaters
Gymnosperms are simple and primitive seed-bearing
plants without flowers.
The plant body is sporophytic and is differentiated
into root,stem and leaves.
All gymnosperms are usually wind-pollinated.
Leaves have thick cuticle and sunken stomata.
Gymnosperms are heterosporous.magasporangia
and microsporangia occur on mega and
microsporophylls respectively.

72. Economic importance of
gymnosperms
sed for making
egetables.
ith of
As food
Seeds of some species are edible: Cycas, Ginko, Pinus,
Gnetum
The seeds and stems of cycas yield ‘sago’ which is a
starch and is also called “arrow root”.
Zamia is a rich source of starch.
Seeds and stem of Cycas revoluta u
wine.
young leaves of Cycas cooked as v
kaffir bread’ prepared from the stem p
Encephalartos.

73. Cycas Cycas seeds

74. Ginko Ginko seeds

75. Pinus Pinus seeds

76. Gnetum Gnetum seeds

78. As medicine
Ephedrine(alkaloid) extracted from Ephedra used in
treating asthma, cough, cold, bronchitis etc.
Tincture of Ephedra is a cardiac stimulant.
Anti cancerous drug called taxol, is obtained from
the bark of Taxus.
The juice is extracted from young leaves of Cycas
revoluta is used for curing blood vomiting and
flatulence.
In Assam the pounded stem of Cycas pectinata is
used as a hair wash for diseased hair roots.

79. Ephreda

80. As ornaments
Species of Cycas are used for decoration
purposes.
Ginkgo bioloba possess beautiful ornamental
leaves.
Thuja, Pinus, Taxus etc are grown in parks.

81. T
axus

82. In industry
1.Gum- Cycas gum used as a adhesive, antidote
for snake bites and using malignant ulcers.
2.Tannins- Tannins are used in leather industry and
it is extracted from the bark of Araucaria, Sequoia
etc.
3.Canada balsam- it is turpentine obtained from
Abies balsamea and used as a mounting medium
in biological preparations.
4.Amber- it is a fossil resin obtained from Pinus
succinifera. Wood of pinus is used for doors,
poles, beams, railway wagon flooring etc.
5.Plywood is prepared from Podocarpus.
6.Papers like newsprints, writing and printing

83. Tannins are prepared from the bark of Araucaria and
Sequoia

86. Porocarpus

87. 7.The leaves of Cycads are used for preparing
baskets, mats, hats, brooms etc.
8.The fibers obtained from the leaves of Cycas and
Macrozamia are used for stuffing pillows and
making mattresses.
Source of oils
*Oil extracted from seeds of C.revoluta, Macrozamia,
Pinus cembra and Cephalotaxus drupacea are
used as edible oils.
*Red cedar wood oil extracted from the heart wood of
Juniperus virgiana is used for cleaning microscopic
preparations and for oil immersion lenses.
*Oils obtained from Cedrus deodara, Ciyptomeria
japonica and Cupressusserm perivirens are used
in preparations of perfumes.

88. Thank you

90. 1. Coniferophyta
Conifers include Pines, Firs, Spruces,Yews,
Junipers, Cedars, Cypress, and Redwoods

91. 1. Coniferophyta
The term conifer comes from the reproductive
structure, the cone, which is a cluster of
scalelikesporophylls
About 550species

92. 1. Coniferophyta
Many conifers areevergreen

93. 1. Coniferophyta
They have long, thin, needle-shaped leaves (Cypress)

94. 1. Coniferophyta
Some plants have broad and flat leaves

95. 1. Coniferophyta
Well adapted in drier climates

97. 2. Cycadophyta
• Seed plants made up of only three living families
• Members are scattered around the globe but are
restricted to tropical or subtropical climates
• The cycads radiated and spread widely in the
early Mesozoic
• Dioecius

99. 3. Ginkgophyta
Ginkgos produce bad smelling fruites
Used as medicinal plants

101. 4. Gnetophyta
They are closely related with conifers
This likeness leads scientists to believe that gnetales
are evolved fromconifers
Thistheory is supported by extensivefossil records,
some dating back to the Palezoic era
Though they are non-flowering plants, gnetales
have a reproductive structure similiar to that of
flowering plants

103. Habitatof Gymnosperms
Occupy large areas of the Earth's surface
Can grow in drier conditions
Gnetophytes grow at high altitudes
Cycads are distributed throughout the world but
are concentrated in equatorial regions

104. Habitatof Gymnosperms. Cont…
Gymnosperms that occupy areas of the world with
severe climatic conditions are adapted to
conserving water;
leaves are covered with a heavy, waxy cuticle
and pores (stomata) are sunken below the leaf
surface to decrease the rate of evaporation

106. Lifecycle
The gymnosperm (pine tree) life cycle takes about
two years to complete
Exhibits alternation of generation
The dominant photosynthetic part of the life cycle
is the sporophyte
Sporophyte is diploid (2n)
Gametophyte (n) is dependent onsporophyte
Cones are reproductivestructures(Gametophytes)
Pollen grains are produced by male cones and
carried to female cone by wind where fertilization
occurs
After fertilization, a sporophyte is formed which i
s
enclosed in a seed. It germinates to produce a
sporophytic plant once again

109. Ecological Importance
Provide food and habitat for wild life
Forests prevent soilerosion
Reduce green housegases
Conifers are often featured in gardens
Junipers are low-growing shrubs and are cultivated
to cover grounds
Conifers are affective wind breakers

110. Economical Importance
T
hey are major source of lumber, paper pulp,
turpentine and resins
They are used asfuel
They are major source of world’s timber
Used as medicines (Ginkgos)
are widely used as
Source of food (Pine Nuts)
Gymnospermous plants
ornamentals

111. Classification of
GYMNOSPERM

112. Classification
• Gymnosperms include a number of fossil and living
forms. They include the primitive members of the
Spermophyta (seed- bearing plants) and form a link
between the Pteridophyta on the one hand and the
angiosperms on the other. Various attempts have been
made by different workers to classify the Gymnosperms.
• One of the earliest attempts was made by Bentham and
Hooker (1866-1883), when they divided seed bearing
plants into Dicots, Gymnosperms and Monocots.
Gymnosperms were further divided into Cycadaceae,
Gnetaceae and Coniferae. Engler (1885) divided
Gymnosperms into seven groups as follows: 1.
Cycadofilicales 2. Cycadales 3. Bennittitales 4.
Cordaitales 5. Ginkgoales 6. Coniferales 7. Gnetales

113. • Coulter and Chamberlain (1917) adapted Engler’s system
with slight modifications and divided gymnosperms into seven
orders: Cycadofilicales, Cycadales, Bennittitales, Cordaitales,
Coniferales, Ginkgoales and Gnetales. He further divided
order Coniferales into two families (Pinaceae and Taxaceae)
and six sub-families as follows:
Families Sub-families
• Orders
• Cycadofilicales
• Cycadales
• Bennittitales
• Cordaitales
• Coniferales
•
Pinaceae Abietineae, Taxodineae, Cupressineae ,
Araucarineae
• Taxaceae Taxineae, Podocarpineae
• Ginkgoales
• Gnetales

114. • Depending upon the composition of wood, Seward
(1919) divided gymnosperms into two classes: i)
Manoxylic with loose textured and porous wood, and
ii) Pycnoxylic with compact wood. Orders Cycadales,
Cycadeoidales and Cycadofilicales were included in the
former whereas, the latter included the orders
Cordaitales, Ginkgoales, Coniferales and Gnetales.
• Prof. Birbal Sahni (1920) classified gymnosperms into
two divisions depending upon the axial or foliar origin of
the ovules. These are: i) Stachyspermae – in which the
ovules arise on the axial organs, and ii)
Phyllospermae – in which the ovules are borne on
leaves. Stachyspermae was further divided into four
orders and Phyllospermae into three orders as follows:

115. • Divisions Orders
• Stachyspermae Cordaitales, Coniferales
• Ginkgoales, Gnetales
• Gymnosperms
Phyllospermae Cycadofilicales, Bennittitales
• Cycadales
• Chamberlain (1934) however, divided the gymnosperms into two large
groups A. Cycadophyta and B. Coniferophyta.
• In the Cycadophyta, sporophylls are in cones.
• They include three orders:
• Cycadofilicales (Pteridospermae)-extinct
• Bennettitales (Cycadeoideales)-extinct
• Cycadales-Mesozoic to present day.
• The Coniferophyta is divided into four orders:
• Ginkgoales-Palaeozoic to present day.
• Cordaitales-extinct
• Coniferales-Palaeozoic to present day
• Gnetales-Recent.

116. • Raizada and Sahni (1938) have summarized the
classification of gymnosperms as follows:
• Cycadophytes:
• Pteridospermae (Cycadofilicales)-Carboniferous. Extinct.
• Cycadeoideales (Bennettitales)-Mesozoic. Extinct.
• Cycadales-Mesozoic to present day.
• Pentoxylales: Jurassic
• Coniferophytes:
• Cordaitales-Palaeozoic. Exinct
• Ginkgoales-Palaeozoic to present day.
• Coniferales-Palaeozoic-Mesozoic to present day
• Gnetales-Recent.

117. • Chamberlain (1935) classified gymnosperms into:
•
•
Gymnosperms with profusely
branched trunks, leaves simple
(needle-like, scale-like or
laminate), stems with small pith
and cortex. Secondary xylem
cylinder massive and less
parenchymatous (pycnoxylic
wood). The group includes extinct
as well as extant orders like
Gymnosperms with fern-like pinnatifid
leaves, weakly branched large globose
or columnar trunks, having large
conspicuously developed pith and
cortical zones in stem. Secondary xylem
cylinder small, composed mainly of
tracheids and abundant parenchyma
(manoxylic wood). Group well
represented in fossil record. The only
surviving representatives are the modern
cycads.
Orders 1. Cycadofilicales 2.
Bennettitales 3. Cycadales Orders: 1. Cordaitales 2. Voltziales 3.
Coniferales 4. Ginkgoales 5. Gnetales
Coniferophytes
Cycadophytes
Gymnosperms

118. • In 1957 prof. D.D PANT gave the modification of
Arnold`s classification and gave the following system..
Cycadophyta Chlamydospermophyta Conifrophyta
CLASS-1-
Pteridospermopsida
Orders-
Lygniopteridales
Medullosales
Glossopteridales
Peltaspermales
Corystospermales
Caytoniales
CLASS-2-
Cycadopsida
Orders-
Cycadales
CLASS-3-
Pentaxylopsida
Orders-
Pentoxylales
CLASS-4-
Bennettitopsida
Orders-
Bennettitales
CLASS-1-
Gnetopsida
ORDERS-
Gnetales
Welwitschiales
CLASS-1-
Coniferopsida
Orders-
Corditales
Coniferales
Ginkgoales
CLASS-2-
Ephedropsida
Orders-
Ephedrales
CLASS-3-
Czekanowskiales
Orders-
Czekanowskiales
CLASS-4-
T
axopsida
Orders-
Taxales

119. • Kramer & Green (see Kubitzki, 1990) have classified the
Division Gymnosperms into two Subdivision as
• follows:-
•
Cycadophytina Coniferophytina
Classes-
Cycadatae
Order-
Cycadales
Families-
1.Stangeriaceae
2.Boweniaceae
3.Cycadaceae
4.Zamiaceae
Classes-
Gnetatae
Orders-
Gnetales
Families-
1.Ephedrac
eae
2.Gnetacea
e
3.Welwitsc
hiaceae
Classes-
Ginkgoatae
Order-
Ginkgoales
Families-
1.Ginkgoace
ae
Classes-
Pinatae
Order- Pinales
(Coniferales)
Families-
1. Taxaceae
2.Cephalotaxaceae
3.Phyllocladaceae
4. Podocarpaceae
5. Araucariaceae 6.
Sciadopityaceae 7.
Taxodiaceae
8.Cupressaceae 9.
Pinaceae

120. Flow charts showing classification by
different workers:-

123. • The modern gymnosperms are commonly grouped
under four orders:
• 1. Cycadales;
• 2. Ginkgoales;
• 3. Coniferales and
• 4. Gnetales
• The Cycadales and the Ginkgoales include living
members which have a long, fossil history and can be
regarded as ‘living fossils’. Ginkgoales in the past (early
Mesozoic) were represented by widely distributed group
of plants, but now the order is represented by a single
species Ginkgo biloba.
• The Coniferales from the most conspicuous order of the
living gymnosperms and include the plants like Pinus,
Cedrus, Abies, Juniperus, Cupressus, Biota, etc.
• The Gnetales are represented by three living genera,
e.g., Gnetum, Ephedra and Welwitschia.

124. Living Gymnosperms
Cycads
Gnetophytes
Ginkgoes
Conifers

125. •

127. • The trees are branched,woody and perennial.
• The leaves are dimorphic scaly and foliar.
• Tap root system mostly associated with fungi
[mycorrhizal association]
• Reproductive structures are formed on leaves which
arrange to form cones male and female cones are
formed sepratly.
• Pollen grains are wind spread and embryo formed is di
to polycotylednous

128. The Largest and the
Oldest Plants are
both Conifers
• Bristlecone pines of
the California White
Mountains are the
oldest
Giant Sequoias of
the California
Sierras are the
largest

129. Earth"
- General
Sherman
-
2200 years old , 275 feet tall ,
30 feet in diameter at the base.
119.3 miles of 1X12 planks
Sequoia
National
Forest, CA

130. There are seven living families of
Conifers
Norfolk Island Pines
Junipers and Cedars
Yew
Sequoias and Redwoods
Pines, Fir Spruce
Five of
the most
familiar

131. • The division coniferophyta contain following 7-families.
• PINACEAE
• It is composed of 10 genera Cedrus, Pinus, Cathaya,
Tsuga,Abies etc.
• Tall and well branched trees.
• Posses dwarf and long shoot
dwarf shoot posses scaly and
needle like foliar leaves.

133. Taxodiaceae
• Comparises evergreen or deciduous trees and plant
parts are mostly spirally arranged.
• Both male and female cones are arranged on same
plants.
• Contain ovuliferous scales with 2 to 9 ovules on each.
• Pollen grains are wingless and lack prothalial cells.
• Seeds may be winged or wingless or irregular in shape.
• Consist of…. Taxodium, Sequoia,
Sequoiadendron, Taiwania, Cunninghamia
etc.

135. Cupressaceae
• The family comparises evergreen much branched trees
or shrubs.
• The plant parts are arranged opposite decussate or in
whorls of 3 or 4.
• Juvenile leaves may be linear adenate or adpressed
completely hiding the stem.
• Leaves may be glandular and grooved.
• Male and female cones occur on same plant.
• There are nearly 22 genera some are.. Tetraclinis,
Juniperus, Callitris, Thuja etc

136. THUJA

137. Podocarpaceae
• Leaves are extreamly variable.
• True leaves are small,scale like and are replaced by
phylloclades.
• Phylloclades are flattened much branched with
fiabelliform.
• Male and female cones are seprate solitary axile or
terminal.
• It consist of 7 genera some are .. Podocarpus,
Dacrydium,etc

138. Podocarpus
macrophyllus

139. Araucariaceae
• Evergreen and highly resinous trees.
• Leaves are small,stiff,awl-like or large and
leatherhy.
• Plant may be monoecious or dioecious.
• Pollen grain are wingless with multiple
persistant prothalial cells.
• It consist of 2 genera …Araucaria,
Agathis .

140. Cephalotaxaceae
• Cephalotaxaceae is a monogenic family with only one
genera Cephalotaxus.
• Named such due to shape of male cone from the greek
word “kephale” means head.
• Male cones are present in globose heads.
• Shrubs or small yew like dioecious plants.
• Male trees posses unbranched shoot.
• Leaves are more or less same size
,falcate,subacute,base round,and whitish beneath.

142. Taxaceae
• These are much branched evergreen woody shrub or
small,rarely large trees.
• The leaves are simple,linear and small and sre spirally
arranged.
• The wood is pycnoxylic.
• Plant is dioecious with male strobilus consist of a cone
axis.
• The family is represented by 5 living genera….
Amentotaxus,
Torreya,Taxus,Psedotaxus,Austrotaxus.

144. 2
Cycadophyta

146. CYCADOPHYTA
• Rarely branched trunks with soft pithy wood.
• Plants are dioceous in nature with compound leaves.
• Microsporangia (Male gametophyte) grows within the
ovule.
• Male gametes are multicilliated and motile.
• Motile sperm released after several months, sometimes
after the seed has fallen.

147. Cycads Appeared
on Earth
250 MYA
• Reached their
greatest
abundance and
diversity during the
Jurassic
• Declined sharply
during the
Cretaceous
radiation of the
angiosperms.

148. Cycad Stems
• Columnar
• Little branching
• Not very woody

149. Certain roots in Cycads grow
toward the soil surface
Corraloid
Roots

150. A Closer Look at Coralloid Roots
• Grow upward near soil
surface
• Branch to form masses
• Root cortex inhabited by
Cyanobacteria (carry
out nitrogen fixation)

151. Cycads produce pollen and seeds
in cones
• Cones develop at
apex of stem

152. All Cycads are Dioecious
• Individual plants
produce either pollen
cones or seed cones
Cycas revoluta
Pollen Cone
Seed Cone

154. Ginkgophytes – Ginkgo
• Extensive fossil record but…only
1 living species: Ginkgo biloba!
•Highly branched tree withwell developed wood.
•Deciduous, fan-shaped leaves with dichotomous
venation.
•Dioecious: male and female trees
-male: “cone” with lateral stalks bearing
microsporangia
-female: no cone, axis with 2 ovules
(outer integument layer fleshy)
•motile sperm (ancestral

155. Ginkgo – Vegetative Characteristics

156. Ginkgo is Deciduous

157. Ginkgo Stems
• Extensive branching
• Very woody

158. Ginkgo Stems
long shoot spur shoot

159. All Ginkgo trees are Dioecious
• Individual plants produce either pollen “cones” or seed
“cones”
• Produced on spur shoots
C

160. Ginkgo produces a seed with a
fleshy seed coat
• Seed Coat contains
Butyric Acid
• Seed Coat is not
edible

165. Ephedra is a desert shrub

166. Gnetum is a
tropical vine or
small tree

167. Welwitschia is a bizarre plant of an
extremely arid environment

168. Welwitschia
produces only two
adult leaves
Welwitschia forms
a short stem and
deep tap root

201. Thank You