Article: Practical difficulties in the application of the species concept in Albian angiosperm pollen

The definition of palynological species on continuously variable characters can cause difficulties in classifying borderline specimens and lead to blurring of morphological boundaries of the species. One group of grains from the Albian of Portugal with several discrete characters illustrates the difficulty of classifying grains into species where discrete characters are found associated in different combinations over a wide range of morphology of continuously variable characters.