The document discusses the structure and types of stomata. Stomata are microscopic openings on plant surfaces surrounded by guard cells and subsidiary cells. There are four basic types of stomata distinguished by the arrangement of subsidiary cells: anomocytic (no arrangement), anisocytic (one smaller cell), paracytic (subsidiary cells parallel to pore), and diacytic (subsidiary cells perpendicular to pore). Examples of each type are provided. The structures allow for gas exchange and vary between dicotyledonous plant species.

1. STOMATA
Mrs. R. H. Mishal
Incharge HOD, D. Pharm
Sir Dr. M. S. Gosavi College of Pharmaceutical Education
& Research, Nashik.

2. A stoma is a minute epidermal opening with following
characteristics:
• A central cell
• Two kidney shaped similar cells containing
chloroplasts known as Guard cells and varying
number of subsidiary (epidermal) cells covering the
guard cells.
A stoma is made up of a pair of identical guard cells,
forming a pore in centre through which gaseous
exchange takes place.
STOMATA

4. There are 4 basic types of stomata among the
dicotyledons.
These types are distinguished on the basis of arrangements
of the subsidiary cells surrounding the stomata
The four types are:
• Anomocytic type, Ranunculaceae
• Anisocytic type, Curciferae
• Paracytic type, Rubiceae
• Diacytic type, Caryophyllaceae

5. The surrounding epidermal cells have no special
arrangement, they are all similar & there are no
subsidiary cells, so all the cells are normal epidermal
cells without any modification, like stomata of
digitalis.

6. The stomata is surrounded
subsidiary cells, one of them
by 3 or more
is distinctly
Hyoscymus
smaller that the others like in
niger.

7. Each stoma is surrounded by 2 or more subsidiary
cells, 2 of them have their long axes parallel to the
pore, which means that the axes of the subsidiary
cells are parallel to the axes of the pore like the one in
senna leaves.

8. Each stomata is surrounded by 2 subsidiary cells
having their long axes perpendicular to the pore like
in peppermint, Mentha piper.

10. Paracytic or Rubiaceous or parallel- celled stomata:
Coca leaf, senna leaf
Diacytic or caryophyllaceous or cross-celled stomata :
Peppermint, Vasaka
Anisocytic or cruciferous or Unequalcelled stomata:
Belladona, Datura
Anomocytic or ranunculaceous or irregular celled
stomata: Digitalis, Lobelia

11. Thank You