302
H. WALTER AND E. STADELMANN
of succulence and hence dilution of the salt concentration in the cell sap,
(2) regulation by salt excretion in the desalting halophytes with salt
glands, and (3) absence of regulation, leading to a constant but slow increase in the salt concentration during the vegetative period as in some
halophytic Juncus species.
The preceding sections on halophytes indicate that these plants are considerably different from xerophytes in their salt relations. The xerohalophytes, which are characteristic of certain arid zones, have been little
investigated. For this group the water relations as well as the salt relations
are important. Little is known also about the ecophysiology of the sulfate
halophytes and the alkali halophytes. Intensive research is needed in the
natural habitat as well as in the laboratory to advance our very fragmentary
knowledge of the relation of the halophytes to their environment and of the
physiological mechanisms which regulate the increased internal salt concentration. Here also the protoplasmic basis of halophytism is eminent as
a possible clue for better general understanding of salt actions on the individual cell.
ACKNOWLEDGMENTS
This work was supported by the Minnesota Agricultural Experiment Station.
Scientific Journal Series, Paper No. 7332. The authors wish to thank Professor
T. T. Kozlowski, University of Wisconsin, Madison, Wisconsin, for his help for
review of the manuscript. For revision of English and style, thanks is given to
Virginia Pedeliski, University of Minnesota.
REFERENCES
Abd El Rahman, A. A., and Batanouny, K. H. (1965). The water output of
the desert vegetation in the different microhabitats of Wadi Hoff. 7. Ecol.
53, 139-145.
Abd El Rahman, A. A., Batanouny, K. H., and Ezzat, N. H. (1966). Water
economy of barley under desert conditions. Flora {Jena), Abt. B 156, 252-270.
Barrs, H. D. (1968). Determination of water deficits in plant tissues. In "Water
Deficits and Plant Growth" (T. T. Kozlowski, ed.), Vol. 1. pp. 235-368. Academic Press, New York.
Batalin, A. (1876). Cultur der Salzpflanzen. Gartenflora 25, 136-138.
Batanouny, K. H. (1963). Water economy of desert plants in Wadi Hoff. Ph.D.
Thesis, Cairo University.
Bauman, L. (1957). Über die Beziehung zwischen Hydratur und Ertrag. Ber. Deut.
Bot. Ges. 70, 67-78.
Berger-Landefeldt, U. (1959). Beiträge zur Ökologie der Pflanzen nordafrikanischer
Salzpfannen. IV. Vegetation. Vegetatio (Haag), 9, 1-47.
Bernstein, L. (1963). Osmotic adjustment of plants to saline media. II. Dynamic
phase. Amer. J. Bot. 50, 360-370.
H. WALTER AND E. STADELMANN
of succulence and hence dilution of the salt concentration in the cell sap,
(2) regulation by salt excretion in the desalting halophytes with salt
glands, and (3) absence of regulation, leading to a constant but slow increase in the salt concentration during the vegetative period as in some
halophytic Juncus species.
The preceding sections on halophytes indicate that these plants are considerably different from xerophytes in their salt relations. The xerohalophytes, which are characteristic of certain arid zones, have been little
investigated. For this group the water relations as well as the salt relations
are important. Little is known also about the ecophysiology of the sulfate
halophytes and the alkali halophytes. Intensive research is needed in the
natural habitat as well as in the laboratory to advance our very fragmentary
knowledge of the relation of the halophytes to their environment and of the
physiological mechanisms which regulate the increased internal salt concentration. Here also the protoplasmic basis of halophytism is eminent as
a possible clue for better general understanding of salt actions on the individual cell.
ACKNOWLEDGMENTS
This work was supported by the Minnesota Agricultural Experiment Station.
Scientific Journal Series, Paper No. 7332. The authors wish to thank Professor
T. T. Kozlowski, University of Wisconsin, Madison, Wisconsin, for his help for
review of the manuscript. For revision of English and style, thanks is given to
Virginia Pedeliski, University of Minnesota.
REFERENCES
Abd El Rahman, A. A., and Batanouny, K. H. (1965). The water output of
the desert vegetation in the different microhabitats of Wadi Hoff. 7. Ecol.
53, 139-145.
Abd El Rahman, A. A., Batanouny, K. H., and Ezzat, N. H. (1966). Water
economy of barley under desert conditions. Flora {Jena), Abt. B 156, 252-270.
Barrs, H. D. (1968). Determination of water deficits in plant tissues. In "Water
Deficits and Plant Growth" (T. T. Kozlowski, ed.), Vol. 1. pp. 235-368. Academic Press, New York.
Batalin, A. (1876). Cultur der Salzpflanzen. Gartenflora 25, 136-138.
Batanouny, K. H. (1963). Water economy of desert plants in Wadi Hoff. Ph.D.
Thesis, Cairo University.
Bauman, L. (1957). Über die Beziehung zwischen Hydratur und Ertrag. Ber. Deut.
Bot. Ges. 70, 67-78.
Berger-Landefeldt, U. (1959). Beiträge zur Ökologie der Pflanzen nordafrikanischer
Salzpfannen. IV. Vegetation. Vegetatio (Haag), 9, 1-47.
Bernstein, L. (1963). Osmotic adjustment of plants to saline media. II. Dynamic
phase. Amer. J. Bot. 50, 360-370.