Palynotaxonomic studies of <i>Melanoseris</i> Decne. (Cichorieae-Asteraceae) from Western Himalayas, Hindukush and Karakorum ranges

Pollen morphology of ten species and three varieties of the genus Melanoseris Decne. (Cichorieae-Asteraceae) from Western Himalayas, Hindukush and Karakorum ranges was studied. Pollen were examined using light, fluorescent and scanning electron microscopy. Pollen of eight taxa were studied for the first time including four endemic species. Pollen are usually isopolar, spheroidal to oblate-spheroidal, elliptic to rarely circular in equatorial and hexagonal in polar view, trizonocolporate and echinolophate with 15 lacunae. Significant variation has been found mainly in pollen size, number of echinae and ornamentation of the polar area. Pollen ranges from 27 to 56 µm in length and from 30 to 56 µm in diameter. Polar area varies from small to moderately extensive with 2–15 spines. Agglomerative analysis based on 12 pollen character showed the well-defined clustering pattern, explaining total variation and separation of the studied taxa. Two distinct pollen-types: Melanoseris astorensis and Melanoseris macrorhiza were recognised. Keys to pollen-types, and species of each pollen type are provided. An attempt has been made to correlate the results of present palynological studies with that of recent taxonomic treatment and phylogenetic tree of Lactucinae. The pollen morphological data well-support the gross morphological characters at the species and infra-specific level, however, no significant difference was observed in the pollen characters at variety level. The objective of the palynomorphology of Melanoseris is to analyse and describe significant pollen characters across the genus with an aim to delineate species boundaries and also contribute to the positioning of the Melanoseris taxa in future systematic studies.