The polysaccharide components present in the scape of Musa paradisiaca (banana) were fractionated into water-soluble (WSP), EDTA-soluble (EDTA-SP), alkali-soluble (ASP) and alkali-insoluble (AISP) polysaccharide fractions [Anjaneyalu, Jagadish and Raju (1997) Glycoconj. J. 14, 507-512]. The EDTA-SP was further fractionated by iso-amyl alcohol into EDTA-SP-A and EDTA-SP-B. The homogeneity of these two polysaccharides was established by repeated precipitation with iso-amyl alcohol, gel-filtration chromatography and sedimentation analysis. The polysaccharides were characterized by monosaccharide composition analysis, methylation linkage analysis, iodine affinity, ferricyanide number, blue value, hydrolysis with alpha-amylase, gold-electron microscopy and X-ray diffraction spectroscopy. Data from all of these studies suggest that EDTA-SP-A is a branched amylose-type alpha-D-glucan and that EDTA-SP-B is a highly branched amylopectin-type polymer. The nature of the branching patterns of these polysaccharides suggests that they are unique to M. paradisiaca.