Nog eens Polypodium: een nieuw anatomisch-morfologisch kenmerk voor onze drie Europese soorten

The author introduces a new character to distinguish Polypodium vulgare L., P. australe Fée, P. interjectum Shivas, and specimens more or less intermediate between P. interjectum and P. vulgare. They can be identified with the aid of fig. 1. The dark part represents the green mesophyll; the narrow white margin of the segments is hyaline. Fig. 1, a: P. vulgare L.; 1, b: P. interjectum Shivas; 1, c: P. australe Fée; 1, d: intermediate form between P. interjectum and P. vulgare.