Screen Shot 2017-12-12 at 10.06.43

Screen Shot 2017-12-12 at 10.08.50

A scanning electron microscope study of guard cells

by Dayanandan P., Kaufman P. B. (1973)

P . Dayanandan, P . B. Kaufman,
Department of Botany, University of Michigan, Ann Arbor, MI. 48104



in “3lst Ann. Proc. Electron Microscopy Soc. Amer.” New Orleans, La., t973. C. J. Arce-nbaux (ed.). –


A three dimensional appreciation of the guard ce11 morphology coupled with ultrastructural studies should lead to a better understanding of their still obscure dynamics of movement. We have found the SEM of great value not only in studies of the surface details of stomata but also in resolving the structures and relationships that exist between the guard and subsidiary cells. We now report the isolation and SEM studies of guard cells from nine genera of plants.

Guard cells were isolated from the following plants: Psilotum nudum, four species of Equisetum, Cycas revoluta, Ceratozamia sp., Pinus sylvestris, Ephedra cochuma, Welwitschia mirabilis, Euphorbia tirucalli and Allium cepa.





Stomata and Types of Stomata

Bhatia S. C. (2017)

Lesson Prepared Under MHRD project “National Mission on Education Through ICT”

Discipline: Botany

Paper: Plant Anatomy

National Coordinator: Prof. S.C. Bhatla

Lesson: Trichomes and Stomata

Lesson Developer: Dr Smriti Singh

Department/College: Acharya Narender Dev College

Lesson Reviewer: Prof.S.C.Bhatla

Department/College: Botany, University of Delhi

Language Editor: Dr Sonal Bhatnagar

Department/College: Hindu College

Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL


in Trichomes and Stomata – Virtual Learning Environment – University of Delhi, India –

It is an opening/ pore/ intercellular space in the epidermis, through which gaseous exchange takes place in plants. It is surrounded by two specific cells known as guard cells. Stomatal pores together with guard cells are known as stoma. Generally guard cells are bean or crescent shaped in dicots which have dorsiventral or bifacial leaves, and dumbell shaped in monocots which have isobilateral or unifacial leaves. Further, these guard cells are surrounded by various number of cells known as subsidiary cells. This epidermal intercellular space or pore together with guard cells and subsidiary cells is known as stomatal complex (stoma + subsidiary cells). Below the stomata there is intercellular space in mesophyll cells known as stomatal chamber. Stomata are found on young stem, leaves, flower, and fruit. Exceptionally they are also found on roots of Pea (Pisum arvense) and Ceratonia siliqua. Stomata which are found on non-foliar part (flower, fruit, seed) are non functional. Distribution of stomata on leaf surfaces varies from species to species. They may be found on both the surfaces of leaves (adaxial and abaxial) or may be restricted to only one surface. When stomata are found only on upper surface, the leaf is called epistomatic and when found exclusively on lower or abaxial surface, the leaf is called hypostomatic. Frequency of stomata differs from species to species eg 402 in Quercus calliprinos, 1198 in Qlyrata, 176 in Pistacia palaestina and 255 in P. lentiscus. It is found that with decreasing light intensity stomatal frequency decreases. Stomata are often not found on solid masses of cells where there are no intercellular spaces like sclerenchyma of leaf margins and fibre bundles of veins, as these tissues don’t provide space for diffusion of gases. There is an unusual distribution of stomata in some plants like in Saxifraga, they are present only near the leaf tip; in Daphne petraea there is a longitudinal band of stomata on both sides of midrib. A very unusual distribution is found in Mimosa cruenta, where on upper surface there is uniform distribution of stomata, however on the lower surface only one of the longitudinal halves bear stomata and the other half completely lacks them.

Non-green total parasitic (holoparasite) plants lack stomata e.g. Rafflesia (a total root parasite) and Neottia and members of family Balanophoraceae and Monotropaceae. These holoparasites lack cholorophyll, thus they are completely dependant on their host for food. Orobanchae, a achlorophyllous holoparasite possess only few stomata on the stem. Semi parasites like mistletoes (Loranthaceae) depend on host for water synthesizes their food and minerals only, have stomata but lesser in number.

Position of stomata is also governed by climatic conditions. In xerophytic conditions stomata are sunken (at lower level than other epidermal cells) to reduce the water loss. They may be found in cavities, stomatal crypts (Nerium oleander), or in grooves (Ericales) lined with epidermal hair. In some hydrophytes like Nymphaea and Nelumbo with floating leaves, stomata are found only on upper surface. However, there are no stomata in some submerged hydrophytes belonging to families Ceratophyllaceae, Nymphaeaceae, Podostemonaceae and some Ranunculaceae member. Stomata bars are found in Eucalyptus, these are protuberances of cuticle over the guard cells. Guard cells may differ from other epidermal cells in their origin and morphology but chemically they are similar to other epidermal cells. They are rich in mitochondria, endoplasmic reticulum, dictyosomes and vacuoles and fewer grana in plastids but are sufficient for the sustenance of guard cells. There is no plastid in Paphiapedilum an orchid.


Types of stomata

Depending upon the number and arrangement of subsidiary cells around the guard cells stomatal complex has been classified into following types (Tomlinson, 1961, 1974; Metcalfe and Chalk, 1979;). A species can have more than one of the following stomatal complex types, even a single leaf can have more than one type.

  1. Paracytic type– One or more subsidiary cells are arranged parallel to the guard cells. e.g.  Convolvulaceae, Leguminoseae,


Stomata classifications



Classification of stomatal types

by Shodhganga (    )

A. MORPHOLOGICAL OR TOPOGRAPHICAL CLASSIFICATION: The dicotyledons stomata were firstly classified into 4 types by Yesque in the year 1889. The names for your types were given after the family in which these types were first studied. The four types as defined by Yesque (1889) are as follows:


B. MORPHOGENETIC OR ONTOGENETIC CLASSIFICATION: The stoma mother cell or stomatal initial called the meristemoid is cut off from a cell of the protoderm. The stomatal initial undergoes one or more divisions to give rise to a stoma. A stomatal meristemoid which divides to form two equal guard cells is called a guard mother cell.


DISPERSION7OF STOMATA On the lamina, the stomata are more or less uniformely dispersed over the whole surface in between the veins, sometimes over the finer veins but mostly not over the main veins. The stomata are very rarely present over the major veins. In other words, the dispersion of the stomata is homogeneous in most plants. This may not be always true, as stomata are sometimes more numerous on certain parts of leaves and competely absent from other pats. Sometimes, stomata are dispersed in distinct groups. The dispersion of stomata is more or less homogeneous in other foliar organs like lamina, such as stipule, bract, bractiole, calyx, corolla etc.


ORIENTATION OF STOMATA: In foliar organs such as lamina, stipule, bract,^corolla etc, the orientation of stomata may be irregular, while in the cylindrical organs like stem, petiole, peduncle, style, filament of the stamen etc, the orientation of the stomata may be parallel to the long axes or occassionally transverse or oblique.

Size of pollen grains and stomata are effective parameters for analysis of ploidy levels

Photo credit: Google

MALVACEAE – Eriotheca pubescens


Pollen and stomata morphometrics and polyploidy in Eriotheca (Malvaceae‐Bombacoideae)

by Marinho R. C., Mendes‐Rodrigues C., Bonetti A. M., Oliveira P. E., Peeters T. (xxxx)

in Plant Biology 16(2): 508 – 511 – DOI10.1111/plb.12135 –


Approximately 70% of the angiosperm species are polyploid, an important phenomenon in the evolution of those plants. But ploidy estimates have often been hindered because of the small size and large number of chromosomes in many tropical groups. Since polyploidy affects cell size, morphometric analyses of pollen grains and stomata have been used to infer ploidy level.

Polyploidy is present in many species of the Cerrado, the Neotropical savanna region in Central Brazil, and has been linked to apomixis in some taxa. Eriotheca gracilipes and Eriotheca pubescens are common tree species in this region, and present cytotypes that form reproductive mosaics. Hexaploid individuals (2n = 6x = 276) are polyembryonic and apomictic, while tetraploid and diploid individuals (2n = 2x = 92, 2n = 4x = 184) are sexual and monoembryonic. We tested whether morphometric analysis can be used to estimate ploidylevels in E. gracilipes and E. pubescens individuals.

Pollen material from diploid and hexaploid individuals of E. gracilipes, and tetraploid and hexaploid individuals of E. pubescens, were fixed in 50% FAA, and expanded leaves were dried in silica gel. Pollen grains and stomata of at least five individuals from each population were measured.

The results demonstrate that all measures were significantly different among cytotypes. Individuals with higher levels of ploidy (hexaploid) all presented measurements that were higher than those with lower levels (diploid and tetraploid). There was no overlap between ploidy levels in each species at 95% confidence interval. Thus, the size of the pollen grains and stomata are effective parameters for analysis of ploidy levels in E. gracilipes and E. pubescens.

Ontogenetic classifications of stomatal complexes

Screen Shot 2017-09-25 at 11.42.10


Ontogenetic basis for classification of stomatal complexes – a reapproach

by Timonin A. C. (1995)

A. C. Timonin, Department of Higher Plants Morphology and Systematics, Biological Faculty, M. V. Lomonosov Moscow State University, Vorobyevy Gory, 119899, Moscow, Russia.

in Flora 190: 189-195 –

Screen Shot 2017-09-25 at 12.53.31


The majority of existing ontogenetic classifications of stomatal complexes is considered to be, in fact, a mixture of structural and ontogenetic ones.

Purely ontogenetic classifications should be based on only three characters:

a) orientation of guard cells’ mother cell division in relation to the plane of the preceding cell division ;

b) orientation of the divisions of cells other than guard cells’ mother cell and

c) number of cell divisions leading to mature stomatal complex formation.

This method would result in three independent and reciprocally supplementary stomatal classifications. The first one consists of only PAYNE’S anomo-, dia-, and parameristic types. The second one contains both PAYNE’S allelo- and helicocytic types and new concentro-, radi-, and tangenticytic stomatal types. For the third classification, monomeristic and bimeristic types, and so forth, are proposed.

Two neglected unnamed STRASBURGER’S and PRANTL’S stomatal types are reintroduced as initial, resp. terminal.

Screen Shot 2017-09-25 at 12.56.22Screen Shot 2017-09-25 at 12.58.50

Morphological features of stomata of tomato cultivars




Analysis of SEM Images of Stomata of Different Tomato Cultivars Based on Morphological Features

Sanyal P., Bhattacharya U., Bandyopadhyay S. K. (2008)

Pritimoy Sanyal, West Bengal Un iv. of Techn., Kolkata, India

Ujjwal Bhattacharya,

Samir K. Bandyopadhyay,


in Modeling & Simulation,, 2008 Second Asia International Conference on Modelling & Simulation (AMS), Kuala Lumpur, Malaysia – DOI: 10.1109/AMS.2008.81


Tomato is one of the important cash crops in the world. There are several varieties of tomato cultivars. Their identifications as well as taxonomy had been studied in the literature using different laboratory methods.
Both morphological and/or genetical characteristics were considered in these available studies. However, to the best of our knowledge, there does not exist any study employing an image analysis based approach. Also, morphological features of stomata of tomato cultivars had not been studied before for the present purpose.
In this article, we report results of our recent study of morphological features of stomata of different tomato cultivars based on their Scanning Electron Microscopy (SEM) images.
Interestingly, these results of the present study are supported by the protein binding pattern of the seeds of respective cultivars.

Variations and modifications of the tricytic stoma



Ontogeny of the tricytic stoma – Variations and modifications.

by Farooqui P. (1981)

Department of Botany, The University, Allahabad, India

Forest Research Centre, Coimbatore, India

Parveen Farooqui

in Proc. Indian Acad. Sci. (Plant Sci.) 90: 85–89 –

Google Scholar –


The tricytic stoma is studied on the basis of published literature and illustrations.

It is found that it may be formed in a variety of ways. These are classified and reviewed.