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distribution oi- ch ar a tomentosa l. ro und the baltic 161
Holland, Ireland, France, Spain. Switzerland, Austria, Hungary,
Rou-mania," Bulgaria," and Turkey and oulside Europé in Asia (Persia,
Sibiria) and Africa (Algeria) |Braun & Nordstedt 1883; Migula 1897;
Groves & Bullcck-Webster 1924; Borza 1936; Verdam 1938).
Verdam also States Central and South America, referring to Robinson
(1906), hut Ihe latter distinctly slutes Ch. ceratophylla Halsted (non
Wallr.) from lliese places. — The fresli water localities in Sweden
are concentrated to limy dislricts and the records from other countries
show the same conditions.
Samuelsson (p. 31) mentions that Ch. tomentosa shows a similar
distribution in Fennoscandia as some other water plants with regard to
ils presence in fresh as well as in brackish water, e.y. 1’otamoycton
pecti-pj.tus, Zannichellia palustris, Scirpus maritimas, Sc. Tabernaemontani,
Ranunculus Baudoin
R. ohtiisiflorns) and he also discusses their
distribution from the ecological and historical points of view. — As an
explanation of the presence of Scirpus maritimus in brackish water as
well as lakes Samuelsson (p. 26) suggests that a high degree of lime of
the water or the ground at the fresh water localities would compensate
the sodium chloride of the sea. This tlieory may be applied to Ch. [-tomen-tosa, if we can accept such an argumentation about an indefinable
»ne-cessity of salt» for a species. However, it is necessarv first lo investigate
whether the Ca-percentage of the Baltic does not cover the presumed
minimum necessitv of lime of the species, and we must also have an idea
of the pll-conditions in the areas of brackish water, where the species is
found. Also an investigation must be done of Ihe NaCl-necessity of the
species in areas of water deficient in lime. The numerical vallies of the
Cl-percenlage given by Stroede (p. 42) and Olsen (p. 95) are not
appliciable in this case because the waters investigaled by t hem are very
limy. Nor do Gessner’s investigations give anv answer, as the
cal-careous soil of the Biigen district bas a great influence upon the brackish
water in Ihe inner coves, where Ch. tomentosa is found. - The inland
localities of Ch. tomentosa in Skåne, Östergötland and Västergötland
may easily be interpreted as relicls, because all lliese localities are
situaled below Ihe highest marine shore line. However, a consequense
of such an argumentation would be that Ihe species very well may be
found at the present West Coast of Sweden, because if it endured the
~ The localities in Bulgaria and Roumania are two shore lakes at the Black Sea.
The statement of the Roumanian finding has been verified by a specimen in Herb.
of the Bot. Gardens, Gothenburg (Ch. ceratophylta Wallr., »Flora Romania
Ex-siccata» Nr 1401,1.
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