The leaf tannin of willow-herb [Chamaenerion angustifolium (L.) Scop.].

1. The leaf tannin of willow-herb [Chamaenerion angustifolium (L.) Scop.] has been isolated and separated into two fractions of differing solubility. 2. The tannin contains a penta-O-galloyl-beta-d-glucose core to which further galloyl groups are depsidically bound. 3. The unfractionated tannin contains an average of 10.5 galloyl groups/glucose molecule; the soluble fraction has on average 7.6 galloyl groups/glucose molecule and the less soluble fraction has 12.4. 4. The tannin is a mixture of molecules ranging at least from hepta- to trideca-galloyl-beta-d-glucose. 5. The tannin forms complexes with proteins and the fact that it is a hydrolysable gallotannin has a bearing on the release of nitrogen from the protein of the dead leaf.