Second Chapter Plant Tissues Definition Tissue: the cell group which resource and function is same and morphology and structure is similar , moreover close contact each other.

Section one Sorts and Character Accoding to physiological function and shape and structure , including meristem , fundamental tissue , protective tissue , mechanical tissue , conducting tissue and secretory tissue.

一.The Meristems Character, intense ability of meristem,cells are almost isodiametric with no intercellular space , and cell walls are thin with dense cytoplasm ,cells possess big nucleus without obvious vacuole.

Accoding to location , including ⑴apical meristem ( root tip and top stem), up grow , as a result root grow longer and stem get higher.

⑵lateral meristem , (locate around the stem and root ) as a result root and stem get thicker. ⑶intercalary meristem , (base of node and leaf etc ) like shallot or leek

According to resource , including ⑴promeristem ⑵primary meristem ⑶secondary meristem

二.Parenchyma（Ground Tissue） Character , cells is biger, arranged loosely , various shapes ( circular , oval , rectangle , polygonal etc) and possess assimilative , store , absorbing , aerating function . So we can say Parenchyma ：the Vegetative Tissues Carrying out Multiple Functions.

Types: ordinary parenchyma assimilation parenchyma storage parenchyma absorbtion parenchyma aerenchyma

storage parenchyma assimilation parenchyma Aerenchyma1.bulliformcell2.mesophyll 3.vascular bundle4.air cavity5.midrib absorbtion parenchyma

三.Protective Tissue （一）Epidermis：the Primary Protective Tissue Character , flat quadrate,polygonal , irregular etc , moreover , table mutually , no intercellular space , possess nucleus , vacuole and little cytoplasm , no chloroplast with leucoplast and chromoplast , protecting function.

⑶anisocytic type , 3-4 asymmetry accessory cells ⑴paracytic type , two accessory cells , long axises of guard cell and stoma is parallel ⑵diacytic type, two accessory cells , long axises of guard cell and stoma is uprightness ⑶anisocytic type , 3-4 asymmetry accessory cells 1.paracytic type 2.diacytic type 3.anisocytic type

⑷anomocytic type , variable , similar size of accessory cells ⑸actinocytic type, variable and circular , smaller accessory cells than epidermis 4.anomocytic type 5.actinocytic type

non-glandular hair , no varicose bulbiform head and secretive function 2.trichome glandular hair , varicose bulbiform head with secretive function and club-shaped stalk ▲But glandular scale only have varicose bulbiform head. non-glandular hair , no varicose bulbiform head and secretive function

glandular hair glandular scale non-glandular hair non-glandular hair

（二）Periderm：the Secondary protective Tissue phellem phellogen phelloderm

1.Cuticle 2.epidermis 3.phellem 4.phellogen 5.phelloderm 6.cortex Periderm 1.Cuticle 2.epidermis 3.phellem 4.phellogen 5.phelloderm 6.cortex

Definition Lenticel Periderm and lenticel 1.Origination of phellogen 2.epidermis 3.phellogen 4.phellem 5.phelloderm 6.cortex parenchyma 7.supplementary cell

四.Mechanical Tissue Character , leptosomatic , all-sided or parted thickenning of cell walls with stability and substain .Including collenchyma and sclerenchyma.

(一)collenchyma thick wall at their corners , therefore they are life cells .(Mentha canadaensis)

Transverse and longitudinal section of collenchyma

（二）sclerenchyma All-sided thickenning secondary walls , lignification with hilum and pit , lumina is smaller.

1.fibre fusiform cells with thickened walls , and smaller or even unclear lumina . ( Cortex Cinnsmomum and Glycyrrhiza uralensis ) Types xylem fibre , extraxylary fibre , seprate fibre , intercalary crystal fibre , crystal fibre

⒈～⒎fibre⒍seprate fibre ⒏intercalary crystal fibre ⒐crystal fibre sclerenchyma ⒈～⒎fibre⒍seprate fibre ⒏intercalary crystal fibre ⒐crystal fibre

2.stone cell Intensely thicken cell walls and lumina obviously reduce . (Pyrus sp. Phellodendron amuranse)

五．Conducting Tissue Character , transport water and nutritious matter (photosynthesis) . Including vessel , tracheid and sieve tube , companion cell , sieve cell .

(一)vessel and tracheid Series of long tubal or canister-formed vessel member with various pit ( evenly thickened secondary wall) Types annular vessel , spiral vessel , scalariform vessel , reticulate vessel and pited vessel

⒋⒌⒍spiral vessel ⒎scalariform vessel Types of vessel ⒈xylem parenchyma　 ⒉⒊annular vessel　 ⒋⒌⒍spiral vessel 　 ⒎scalariform vessel　 ⒏reticulate vessel　 ⒐pitted vessel

annular vessel　 spiral vessel

scalariform vessel　 reticulate vessel pitted vessel

2.tracheid The type of tracheid 1.Annular～2.spiral～3.scalariform～4.pitted～

(二)sieve tube , companion cell and sieve cell

Sieve tube and companion cell Ⅰ.longitudinal section Ⅱ.transverse section ⒈sieve plate　⒉sieve tube　⒊companion cell　⒋leucoplast　⒌phloem parenchyma

六.Secretory Tissue Character , secrete some special matter , like volatile oil , latex , grume , resin etc. Sorts Exterior secretory tissue Glandular hair nectary

Inner secretory tissue Secretory cell Secretory cavity Secretory canal laticifer

Secretory cavity Lysigenous secretory cavity : several large cavities surrounded by some thin-walled cells and this kind of cavity is formed by the dissolution of parenchyma . so the walls still exist . (volatile oils) for exemple , Citrus reticulata（陈皮）

Schizogenous secretory cavity : It will be noted small cavities of numerous 4-10 intact cells which sometimes contain secretion. for exemple ,Radix Angelica Sinansis（当归）

Section Two Vascular Bundle and Its Type 一.composing Xylem: the Principal Water-Conducting Tissue in Vascular Plants (vessel , tracheid , xylem parenchyma , xylem fiber) Phloem: the Principal Food-Conducting Tissue in Vascular Plants ( sieve tube , companion cell , phloem parenchyma , phloem fiber)

1.closed collateral vascular bundle 二.sorts 1.closed collateral vascular bundle Phloem in exterior , xylem in inner with no cambium(stem of Monocotyledoneae) phloem xylem

2.open collateral vascular bundle it possess cambium(stem of Dicotyledoneae or Gymnospermae) phloem cambium xylem 2.Phloem 3.cambium 4.xylem

3.bicollateral vascular bundle Xylem in middle,phloem in exterior and interior (Solanaceae,Apocynaceae or Asclepiadaceae) phloem xylem phloem

4.amphicribral vascular bundle xylem in middle,there is phloem around (Liliaceae,Gramineae,Polygonaceae or Pteridophyta)

5.amphivasal vascular bundle Phloem in middle,there is xylem around( Rhizoma Acori Tatarinowii)

6.radial vascular bundle Radial arrangement with distant xylem and phloem(primary structere of root of Ditotyledoneae) phloem xylem

Bicollateral vascular bundle Open collateral vascular bundle Closed collateral vascular bundle Amphicribral vascular bundle Amphivasal vascular bundle Radial vascular bundle

Ⅰ open collateral vascular bundle Ⅱ Amphicribral vascular bundle Ⅲ Bicollateral vascular bundle Ⅳ Amphivasal vascular bundle ⅤRadial vascular bundle

Review Questions 一.Definition Periderm , intercalary crystal fibre, crystal fibre , vascular bundle 二.simple answer 1.How about the types and function of the tissue? 2.what is the types of the stoma? 3.what is the trichome ? 4.where is the difference of collenchyma and sclerenchyma?

5.which types has the vessel? 6.what is the exterior and inner secretory tissue?