Palynological Study of the Genus Crepis from Pakistan
Sohail Jamil Qureshi,
Abdul Ghani Awan,
Mir Ajab Khan
Pollen morphology of four different species, Crepis flexuosa, Crepis
multicaulis, Crepis sancta and Crepis thomsonii, belonging
to genus Crepis of family Asteraceae were studied from Pakistan.
Morphology of pollen grains of each of the species is based on 20 specimens
selected at random. Proposed characters i.e., grain, shape of pollen grain,
equatorial view, polar view, equatorial diameter (E), polar diameter (P),
P / E ratio, length of colpus, exine surface, exine thickness, inter poral
distance, inter spinal distance, inter spinal outline, length of spines
and number of spines between colpi in each species were recorded for comparison.
At species level, micromorphological differences and distribution of surface
pattern, shape and size of pollen have been found to exist. The pollen
grains are consistently echinate and trizonocolporate. Maximum equatorial
diameter, polar diameter and colpus length was observed in Crepis multicaulis
while in Crepis flexuosa spine length and exine thickness is found
top be maximum. Inter poral distance is minimum in Crepis flexuosa.
Inter spinal distance & P/E ratio is higher in Crepis thomsonii.
This study demonstrates the potential of pollen studies in distinguishing
some taxonomic groups in the Asteraceae.
Cited References Fulltext