Stomata in Welwitschia (Gymnospermae)

Photo credi: Google

View the 2,000 Year Old Welwitschia mirabilis plants

Some points in the anatomy of leaves of Welwitschia mirabilis

Takeda H. (1913b)

in Ann. of Bot. 27: 347-375 – https://doi.org/10.1093/oxfordjournals.aob.a089462 –

https://academic.oup.com/aob/article-abstract/os-27/2/347/177421/Some-Points-in-the-Anatomy-of-the-Leaf-of?redirectedFrom=PDF

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Stomata in Podocarpus (Gymnospermae)

Photo credit: Google

Podocarpus macrophylla – This is the foliage and blue female cones of the yew pine Podocarpus macrophyllus ‘Maki’. The foliage of the species is shown in the inset.

Cutical micromorphology of Podocarpus, subgenus Podocarpus, section Scytopodium (Podocarpaceae) of Madagascar and South Africa.

by Stockey R. A., Frevel B. J., Woltz P. (1998)

Ruth A. Stockey, Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada

Brenda J. Frevel, Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada

Philippe Woltz, Laboratoire de Morphogenèse Végétale, I.M.E.P. CNRS‐URA 1152, Université d’Aix, Marseille III, Centre St. Jérôme, France

in Int. J. Plant Sci. 159: 923-940 – DOI: 10.1086/297613

http://www.journals.uchicago.edu/doi/abs/10.1086/314089

 

Cuticle micromorphology of leaves from seven species and three varieties of the conifer genus Podocarpus subgenus Podocarpus section Scytopodium from South Africa and Madagascar was studied with scanning electron microscopy.

External and internal features of abaxial and adaxial cuticles are characterized for all taxa and are compared with other known Podocarpus species. External cuticles exhibit Florin rings and stomatal plugs with underlying epidermal cell outlines usually visible.

Leaves are hypostomatic and stomata occur in discontinuous but fairly regular rows in most species. Stomata are oriented parallel to the long axis of the leaf and usually lack polar subsidiary cells. From two to six subsidiary cells occur, with two or three being the most common.

Internal cuticle on subsidiary cell surfaces is granular to rugose, usually with a deep groove corresponding to the external Florin ring. Cuticle on guard cell surfaces is granular or rugose to pitted, and prominent polar extensions are present in all species.

Epidermal cell outlines are undulating and cuticle on epidermal cell surfaces is granular to rugose and pitted.

The most useful characters to distinguish species of this section are the micromorphology of cuticle on the guard cell and subsidiary cell surfaces, epidermal cell shapes, and sometimes the length of polar extensions.

Stomata in Dacrydium (Podocarpaceae)

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Rimu Dacrydium cupressinum

Cutical micromorphology of Dacrydium (Podocarpaceae) from New Caledonia.

by Stockey R. A., Ko H.  (1990)

Ruth A. Stockey,

Helen Ko,

in Bot. Gazette 151: 138-149 – (ISSN: 0006-8071) – DOI : 10.1086/337813

http://www.journals.uchicago.edu/doi/abs/10.1086/337813

 

Cuticle micromorphology of herbarium and of preserved leaves of four species of the genus Dacrydium was studied with scanning electron microscopy.

Dacrydium araucarioides, D. balansae, D. guillauminii, and D. lycopodioides from New Caledonia are all representatives of the tropical subgroup of the genus.

External and internal features of abaxial and adaxial cuticles are characterized for all taxa. External cuticle surfaces of all species lack the Florin rings present in other members of the Podocarpaceae.

Sunken stomata in discontinuous rows characterize all taxa. Subsidiary cell number varies from two to five. Epidermal cell outlines are very sinuous, and cuticle from cell surfaces is smooth to slightly pitted.

Cuticle on guard cell surfaces distinguishes the taxa. Micromorphological features are compared with other previously studied genera in the Podocarpaceae. The New Caledonian species of the genus Dacrydium show a close similarity to each other in micromorphological features of leaf cuticle and are easily distinguishable from other podocarp genera.

The stomatal regions of Picea glauca and Pinus divaricata

 

 

A close up of the stomatal regions of white spruce and jack pine

provides a possible clue to their differing response to foliar herbicides

Lehela A. R., Day R. J., Koran Z. (1972)

in For. Chron. Feb. 1972: 32-34 –

http://pubs.cif-ifc.org/doi/pdf/10.5558/tfc48032-1

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Wax-filled stomatal antechambers are excellent antitranspirants.

 

 

Epicuticular wax in the stomatal antechamber of sitka spruce and its effect on the diffusion of water vapour and carbon dioxide

by Jeffree C. E., Johnson R. P. C., Jarvis P. G. (1971)

Department of Botany, University of Aberdeen, Aberdeen, Scotland

in Planta 98: 1-10 – DOI: 10.1007/BF00387018

https://link.springer.com/article/10.1007/BF00387018

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Summary

The distribution of wax tubes on the leaf surfaces is described, especially the presence of wax tubes in the antechambers of the stomata.

The extra resistances which the wax-filled antechambers add to the other resistances in the pathway for diffusion of water vapour and of carbon dioxide are calculated. We conclude that the wax-filled stomatal antechambers reduce the rate of transpiration by about two thirds but reduce the rate of photosynthesis by only about one third. Thus wax-filled stomatal antechambers are excellent antitranspirants.

Variation with tree age of needle cuticle topography and stomatal structure in Pinus radiata

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Pinus radiata (Radiata Pine, Monterey Pine

Variation with tree age of needle cuticle topography and stomatal structure in Pinus radiata D. Don.

by Franich R. A., Wells L. G., Barnett J. R.  (1977)

in Ann. Bot. 41: 621-626 – https://doi.org/10.1093/oxfordjournals.aob.a085331

https://www.jstor.org/stable/42754183?seq=1#page_scan_tab_contents

Abstract

Scanning electron microscopy reveals differences in the surface topography and stomatal structure of 1-year-old needles of Pinus radiata sampled from trees of different ages.
The cuticular ridges on young-tree needles show an even pitch, whereas the ridges on mature-tree needles appear slightly puckered, with small discontinuities.
The stomata on mature-tree needles have a smaller pore (10-15 µm) than young-tree needles (15-20 µm). In young trees a fine rodlet, or tubular wax covers the walls of the guard and subsidiary cells.
The stomatal antechamber predominating in mature-tree needles contains an amorphous wax, which frequently closes the pore between the overarching stomatal lips.
The yield of crude wax from chloroform extracts of needles of trees of all ages is approximately 0·2 per cent, and there is more of the acidic component in the wax of mature-tree needles.
It is suggested that wax occlusions within the stomatal antechamber of P. radiata may contribute to mature-tree resistance to the needle pathogen, Dothistroma pini Hulbary.

Stomatal size and frequency in Pinus (Gymnospermae)

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Pinus resinosa – Red pine, pine cones, note the marks left on the twig …

Stomatal characteristics of Pinus resinosa and Pinus strobus in relation to transpiration and antitransparant efficiency

by Davies W. J., Kozlovski T. T., Lee K. J. (1974)

in Can. J. For. Res. 4: 571-574 – https://doi.org/10.1139/x74-086 –

http://www.nrcresearchpress.com/doi/abs/10.1139/x74-086?journalCode=cjfr

ABSTRACT

Transpiration rates were much higher in Pinus resinosa than Pstrobus, reflecting greater stomatal size and frequency in the former.

In both species silicone antitranspirant formed stomatal plugs and greatly reduced transpiration.