ANATOMY OF FLOWERING PLANTS

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.
•Single layered

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