Zs. P. Komáromy szerk.: Studia Botanica Hungarica 16. 1982 (Budapest, 1982)

Stollmayerné Boncz, Emilia: The flora of the Csömör pool

STUDIA BOTANICA HUNGARICA (Antea: Fragmenta Botanica) XVI. 1982 P- 73

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82 The Flora of the Csömör pool By E. STOLLMAYER-BONCZ (Received September 30, 1981) Abstract: There is a pool in the district of Csömör village, Pest county, surrounded by agricultural territory. There is a "island" which gives a home to many species, known only from some peat-bogs in Hungary. These and other plants are surveyed by the author. The natural geographical conditions of the Csömör pool and its surroundings The small pool near the Csömör can be found in the left-side lateral valley of the stream Forrás, surrounded by agricultural territories. It is marked by the OMMI genetic soil map as agriculturally untillable land. It cannot be found on maps, probably because of its dimension. There is a strip of water side land of varying width and diversified microrelief, leading from the road to the shore. There is not much open water, however, in spring and summer it makes getting onto the island more difficult. The island itself is a botanically unexploited Sphagnum moor of varied flora. From a botanic point of view the newly explored territory can be found on the northern Pest-Plain part of the Dunamenti-Plain of varied relief, broken by alluvial aprons in the leftside lateral valley of the stream Forrás or Csömör. The stream Forrás is one of the third-rate, left-side affluents of the Danube; its water runs into the stream Mogyoród which is the rightside current of the stream Szilas (Table 1). The currents of the territory (the Rákos, Szilas, Csömör or Forrás and Mogyoród streams) are fed by springs seeping through the surface of Pliocene-Miocene strata on its eastern border (Marosi & Szilárd 1967). The pH of the pool's water was 6.5 to 7.0, determined by universal test paper at the spot. The stream Forrás takes its source in the side of the bench No. 5 of the Danube without an Table 1. The most important characteristics of the Pest-Plain: Its territory: Mean annual temperature: Annual precipitation: Annual evaporation: Annual outlet: 700 km

2 10°C 600 mm 525 mm 2.5 1/sec/km