Principle:-

Stomata:-

Epidermal structure, posses great diagnostic value & importance in quantitatively microscopy.

A stomata is made up of two identical guard cells forming a pore in center. (stomata : pores as opening) during the formation of a stomata the surrounding cells cut off from the monter epidermal cells & get slightly different shape & size & these cells are called as subsidiary cells. On the basis of the characteristic of the guard cell & subsidiary cell. Stomata can be classified.

By variations in the turgidity of the guard cells the size of the pores is altered. Stomata take part in transpiration & respiration stomata’s are entirely absent in submerged leaves of aquatic plants.

STOMATA

According to the characters of guard cells.

Moss Type united guard cells.

Gymnospermous oval & partially lignified guard cells.

Gramineous, dumbbell shaped guard cells .

Dicatyle donous Arcuate guard cells (Bean shaped)

Eg. Funaria

Eg. Saviu.

Eg.family graminae & cyperaceae

Moss Type united guard cells.

Gymnospermous oval & partially lignified guard cells.

Gramineous, dumbbell shaped guard cells .

Dicatyle donous Arcuate guard cells (Bean shaped)

Eg. Funaria

Eg. Saviu.

Eg.family graminae & cyperaceae

Dicotyledonous stomata

According to number nature & arranged of subsidiary cells.

PARACYTIC

DIACYTIC

ANIMOCYTIC

(Rubiceous or parallel celled) Long axis of two subsidiary cells is parallel to trat of stomata.

Eg. Senna, coca.

(caryophyllus or cross celled) Long axis of a subsidiary cells is at right angle to that of the stomata. Eg. Peppermint, vasaka,spearmint.

(Ranunoculaceous or irregular celled.) The stomata is surrounding by varing number of cells in number of ways different from epidermis eg. Digitallis.

ANISOCYTIC

ACTINOCYTIC

(cruciferous & unequal celled)The stomata is surrounded by 3 subsidiary cells of which one is markedly smaller than other.eg. Belladona, Datura.

Subsidiary cells are arranged radially

Function And Distribution Of Stomata.

Stomata perform the function of gaseous exchange and transpiration in the plant body. Stomata are most abundant in the lower epidermis of a dorsiventral leaf less abundant on the upper. In an isobilateral leaf , stomata remains confined to the upper epidermis alone in sunmerged leaves no stomata is present .In cocca , Buchu & cherry the stomata is present only on lower surface while in case of senna belladonna datura etc. stomata are present on both the surface. The distribution of stoma shows great variation between upper &lower epidermis.

Procedure:

Take a leaf whose stomata has to be observed peel off a thin section from the leaf. Clean the thin section by warming it slightly with chloral hydrate to remove the epidermal part.Wash the thin section with water & dip it in saffrain to stain it about nearly for 2 mins.Wash the section place it on glass slide & place a drop of glycerine on it. Put a coverslip & observe the stomata at 10 × 4 Draw the stomata on black chart paper by the help of camera lucida & determine its characteristics.