Pollen morphology of the genus Pedicularis L. Orobanchaceae from Pakistan and Kashmir and its taxonomic implications

摘要

Pollen morphology of 22 species of the genus Pedicularis L. belonging to 11 series from Pakistan and Kashmir was examined by light and scanning electron microscope. Out of 22 species, pollen of 16 species were examined for the first time, of which 6 species were endemic to the area under consideration. The genus Pedicularis is a ± eurypalynous taxon. Pollen grains are usually radially symmetrical, isopolar, tri-syncolpate and bi-syncolpate, prolate-spheroidal, oblate-spheroidal, sub-prolate rarely prolate. Sexine is slightly thicker than nexine or as thick as nexine. Tectum is quite variable, ranging from psilate to fine-medium scabrate-punctate or micro-foveolate-rugulate. On the basis of exine ornamentation four distinct pollen types viz., Pedicularis albida -type, Pedicularis oederi -type, Pedicularis bicornuta -type, and Pedicularis roylei -type were recognized. Little correlation was found between the infrageneric classification and the pollen type. Species belonging to one series (an infrageneric category) may fall in different pollen types or vice versa. However, pollen morphology was significantly helpful at specific level within each pollen type. A strong correlation was found between the aperture configuration and corolla type but without any correlation between the pollen type and the corolla type.