Morphological studies on the nutlet of Turkish Cyclotrichium Manden. & Scheng. (Lamiaceae)

Morphological characters of the nutlets of Cyclotrichium Manden. & Scheng. in Turkey were examined using scanning electron microscopy (SEM). The genus Cyclotrichium is represented by six species in Turkey, of which two are endemic for Turkey. Nutlet morphology of the species was studied using stereoscopic microscopy and SEM, and the features were described and illustrated. Nutlet morphology of the examined specimens exhibits some variation in size, shape and sculpture. Nutlets range from 1.1 to 2.0 mm in length and 0.5 to 1.0 mm in width and are elliptic, oblong to ovoid and trigonous in shape. Nutlet sculpture can be divided into two main types: distinctly or weakly reticulate pattern in C. niveum, C. origanifolium, C. longiflorum and rounded cell arrangement in the remaining species. Micromorphological characters could be useful in solving taxonomic problems of Cyclotrichium.