Morphometrical analyses of Secale (Triticeae, Poaceae)

Abstract
Some fifteen taxa ranked as species or subspecies have generally been recognized within Secale. However, most of these seem impossible to separate on morphology alone. Based on 14 morphological characters considered of diagnostic value and scored on 44 specimens representing most of the taxa a Principal Components Analysis (PCA) was carried out. Limited correlation was found between the characters and consequently the first three principal axes account for only about 60% of the total variation. The PCA shows only a weak separation of annual and perennial taxa. Further analyses mainly of spikelet characters support merging of most of the previously accepted taxa within each of these two groups. A total of three species with five infraspecific taxa are here proposed within the genus and a key is provided to the taxa.