1. 1951∿1953年に亘り苹果砧木ズミの地方分布及び系統に就て北海道, 青森, 長野各地区を調査した。2. 北海道に於てはMalus baccata BORKH. var, mandshurica MAXIM及びMalus sieboldii REHDERの大葉系が分布する。然して前者を砂浜矮性型, 喬木型, 火山灰矮性型の三系統に区分することが出来る。3. 青森県に於てはMalus sieboldii REHDERの大葉系及び小葉系の二系統が野生分布し, 長野県東部地方一帯に於てはMalus sieboldii REHDERの小葉系が野生分布する。The investigations were carried out to know the local distribution and formation of Malus sieboldii REHDER in HOKKAIDO, AOMORI and NAGANO district, during 1951 to 1953. The results may be summarized as follows : Malus baccata BORKH. var, mandshurica MAXIM. and large leaf strain of Malus sieboldii REHDER are distributed in HOKKAIDO. Malus baccata BORKH. var, mandshurica MAXIM. was classificated into three type as follows. 1. dwarf type of sand beach. 2. arborescence type. 3. dwarf type of Volcanic ashes zone. Large leaf strain and small leaf strain of Malus sieboldii REHDER are distributed in AOMORI district, and small leaf strain of Malus sieboldii REHDER are distributed in the eastern part of NAGANO district
