ANATOMY OF FLOWERING PLANTS

1. ANATOMY OF FLOWERING
PLANTS

2. • Study of internal structure of plants is called
ANATOMY.

3. TISSUES
• A tissue is a group of cells having a common
origin and perform a common function.
• Two types: MERISTEMATIC and PERMANENT
tissues

4. MERISTEMATIC TISSUES
• Growth in plants is largely restricted to
specialised regions of active cell division called
meristems. Three types:
• Apical meristems
• Intercalary meristems
• lateral meristems

8. PERMANENT TISSUES
• Structurally and functionally specialised and
lose the ability to divide.
• Having all cells similar in structure and
function – simple tissues
• Having many different types of cells – complex
tissues

9. SIMPLE TISSUES
• Parenchyma
• Collenchyma
• Sclerenchyma

10. PARENCHYMA

11. • Cells are isodiametric – spherical, oval, round,
polygonal or elongated in shape
• Cell walls are thin
• Cellulose
• Closely packed or having intercellular spaces
• Photosynthesis, storage, secretion

14. COLLENCHYMA

16. • Below the epidermis in dicotyledonous plants
• Homogeneous layers or in patches
• Cells are thickened at corners – cellulose,
hemicellulose, pectin
• Contain chloroplast – chlorenchyma
• Intercellular spaces absent
• Mechanical support

17. SCLERENCHYMA
• Long narrow cells with thick and lignified cell
walls having numerous pits
• Dead without protoplasts

18. • FIBRES – thick walled elongated pointed cells

19. • SCLEREIDS – spherical, oval or cylindrical,
highly thickened dead cells with narrow
cavities called LUMEN
• Fruits walls of nuts; pulp of fruits; seed coat of
legumes and leaves of tea
• Mechanical support to organs

23. COMPLEX TISSUES
• Made of more than one type of cells
• Work together as a unit
• Two types; XYLEM and PHLOEM

24. XYLEM
• Conducting tissue for water and minerals from
roots to the stem and leaves
• Mechanical strength
• Four different kinds of elements;
• Tracheids
• Vessels
• Xylem fibres
• Xylem parenchyma

25. TRACHEIDS

26. • Inner layers of the cell walls have thickening
which vary in form

27. VESSELS

28. XYLEM FIBRES

29. XYLEM PARENCHYMA

34. • ENDARCH

36. • EXARCH

38. PHLOEM
• Transport food materials from leaves to the
plant parts.
• Composed of sieve tube elements,
companion cells, phloem parenchyma and
phloem fibres.

39. SIEVE TUBE ELEMENTS
• Long tube like cells
• Arranged longitudinally
• End walls perforated to form sieve plates
• Having cytoplasm and a large vacuole without
nucleus
• Functions controlled by the nucleus of
companion cells

40. COMPANION CELLS
• Specialised parenchymatous cells
• Sieve tube elements and companion cells are
connected through pit fields
• Help in maintaining pressure gradient in the
sieve tubes

43. PHLOEM PARENCHYMA
• Made up of elongated, tapering cylindrical
cells
• Having dense cytoplasm and nucleus
• Cellulose and has pits through which
plasmodesmatal connections exist b/w cells
• Store food and other resins, latex, and
mucilage
• Absent in monocotyledons

45. PHLOEM FIBRES(BLAST FIBRES)
• Made of sclerenchymatous cells
• Absent in primary phloem
• Elongated, unbranched and have pointed
needle like apices
• Thick cell wall
• At maturity fibres loss their protoplasm and
become dead
• Phloem fibres of jute, flax, hemp are
commercially used

47. • Protophloem- sieve tubes are narrow
• Metaphloem- sieve tubes are bigger

48. THE TISSUE SYSTEM
• Based on the structure and location-
• Epidermal tissue system
• Ground or fundamental tissue system
• Vascular or conducting tissue system

49. EPIDERMAL
• Forms outer-most covering of the whole plant
body
• Comprise
1)Epidermal cells
2)Stomata
3)Epidermal appendages – trichomes and hairs
• EPIDERMIS - Outermost layer, elongated,
compactly arranged cells forms continuous
layer.

50. • Outside of epidermis covered with a waxy
thick layer – cuticle – prevents the loss of
water
• Absent in roots

51. • STOMATA – present in epidermis of leaves.
• Regulate the process of transpiration and
gaseous exchange

52. • HAIRS – root hairs are unicellular elongations
of epidermal cells – absorption
• TRICHOMES – multicellular, branched or
unbranched, soft or stiff, secretory
• Preventing water loss due to transpiration

53. GROUND TISSUE SYSTEM
• Except epidermal and vascular bundles
• Consists of simple tissues
• MESOPHYLL

54. VASCULAR TISSUE SYSTEM
• Xylem and phloem together constitute the
vascular bundles
Two types
• Radial
• conjoint

56. DICOTYLEDONOUS STEM

57. • Epidermis – cuticle, trichomes, stomata
• Cortex – three sub zones –
hypodermis
cortical layer
Endodermis – rich in starch grains – starch
sheath
• Pericycle forms a semi-lunar patches of
sclerenchyma
• Medullary rays
• VB are arranged in ring- conjoint, open and
endarch
• Pith

58. MONOCOTYLEDONOUS STEM

59. • Sclerenchymatous hypodermis
• Scattered vascular bundles
• Surrounded by a bundle sheath
• VB are conjoint closed endarch
• Peripheral VB are smaller than central
• Phloem parenchyma absent
• Water contain cavities present in VB

60. DORSIVENTRAL
(DICOTYLEDONOUS)LEAF
• The lamina shows three main parts:
• Epidermis,mesophyll and vascular system
• epidermis-it cover both upper and lower
surface
• Mesophyll-tissue between upper and lower