A morphogenetic basis for plant morphology

A morphogenetic basis for plant morphology

by Sachs T. (1982)

Tsvi Sachs,

In Acta Biotheoretiea 31 a: 118-131 – In: Sattler R. (eds) Axioms and Principles of Plant Construction. Springer, Dordrecht – https://doi.org/10.1007/978-94-009-7636-8_6


Abstract: The Principles Considered

The paper is meant to explain and, where possible, briefly to substantiate the following central principles:

  1. The study of morphology has been based on the concept of homology or the assignment of different structures to one category. Categories based on intuitive groupings have been successful to a degree that merits explanation.
  2. A possible definition of homology that would include both ontogenetic and evolutionary considerations relates not to mature structure but to shared developmental processes.
  3. In the development of plant organs, processes occurring early in primordia generally show a wider homology than any others. (Therefore, categories such as “leaf” may be defined as groups whose members share some very early primordial states.)
  4. Since different processes cannot be expected to evolve at the same average rate, the conservative ones should be used as a basis for morphology. Developmental programs operating early in ontogeny are usually conservative from an evolutionary point of view because when they change there are many important consequences often leading to a disruption of the functional integrity of the mature structures. In plants this conservatism is apparent in meristematic stages of organ development and not in embryos or seedlings.
  5. The evolution of controls for the location, duration and timing of developmental processes could be expected to restrict plants to a limited number of morphological organ categories and to various intermediate organs: the observed facts can therefore be accounted for.

Stomata of Monocot and Dicot Plants

Difference Between Stomata of Monocot and Dicot Plants

by Panawala L. (2017)

Lakna Panawala,

Molecular Biologist, Difference Between, Sydney, Australia


In DifferenceBetweenStomataofMonocotandDicotPlants_DefinitionGuardcellsDistributionofStomata.pdf



Monocot and dicot plants contain stomata in their leaves as well as in their stem. The major role of stomata is to facilitate the gas exchange. They also facilitate transpiration, which helps the absorption of water from the soil and the transport of water through the xylem. The size of the stomata is controlled by a pair of guard cells.

The main difference between stomata of monocot and dicot plants is that the guard cells of the monocots are dumbbell-shaped whereas the guard cells of dicot plants are bean-shaped.

Essay on different charcteristics of stomata

Essay on stomata/stomata/higher plants/Botany

by Bijoy G. (xxxx)

In Biology discussion –



Here is an essay on the ‘Stomata’ for class 11 and 12. Find paragraphs, long and short essays on the ‘Stomata’ especially written for school and college students.

Essay on the Stomata

Essay Contents:

  1. Essay on the Meaning of Stomata
  2. Essay on the Occurrence of Stomata
  3. Essay on the Position of Stomata
  4. Essay on the Structure of Stoma
  5. Essay on the Origin of Stomata
  6. Essay on the Types of Stomata
  7. Essay on the Functions of Stomata

Ontogenetic types of stomata

A new classification of the ontogenetic types of stomata

by Fryns-Claessens E., Van Cotthem W. (1973)

Elisabeth Fryns-Claessens, University of Ghent (Belgium)

Willem R. J. Van Cotthem, University of Ghent (Belgium)


In Bot. Rev. 39(1): 71-138


Epistomatal mucilage plugs

Fig. 1 Evidence for epistomatal mucilage plugs extending into the substomatal cavity (a-i) and effect of mucilage plugs on the leaf water status (j and k). Mucilage-containing plugs in (a- i) were verified by exposure of leaves or leaf pieces to a 0.5% alcian blue solution for 24 h. ( a ), ( b ) and ( c ) microscopical cross- sections of plugged stomata of Drimys winteri, Agathis australis (trivial name Kauri-tree; gymnosperm) and Vitis vinifera ; ( d ), ( e ) and ( f ) top views on the abaxial leaf surface of A. australis , Tristania sumatrana (angiosperm) and Nothofagus dombeyi (angiosperm); ( g ), ( h ) and ( i ) 3-D reconstructions of a stomata on the abaxial leaf surface of Ficus superba (angiosperm), Podocarpus totara (gymnosperm) and Metrosideros excelsa (angiosperm) obtained with a 3-D digital incident-light microscope; ( j ) and ( k ) plots of patch output pressure P p values against the corresponding R.H. 
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Distribution and function of epistomatal mucilage plugs

by Westhoff M., Zimmermann D., Zimmermann G., Gessner P., Wegner L. H., Bentrup F.-W., Zimmermann U. (2009)

M. Westhoff,University of Wuerzburg (Würzburg, Germany)

Dirk Zimmermann, Qiagen, Hilden, germ

G. Zimmermann, University of Wuerzburg (Würzburg, Germany)

Petra Gessner, University of Wuerzburg (Würzburg, Germany)

Lars H. Wegner, Karlsruhe Institute of Technology, Germany

Friedrich-Wilhelm Bentrup, University of Salzburg, Austria

U. Zimmerman, University of Wuerzburg (Würzburg, Germany)


In Protoplasma 235(1-4): 101-105 – DOI: 10.1007/s00709-008-0029-0 –



Investigation of 67 gymnosperm and angiosperm species belonging to 25 orders shows that epistomatal mucilage plugs are a widespread phenomenon.

Measurements of the leaf water status by using the leaf patch clamp pressure technique suggest that the mucilage plugs are involved in moisture uptake and buffering leaf cells against complete turgor pressure loss at low humidity.