| Abstract: | In Parthenium hysterophorus L. four trichome types i.e. (1) cylindrical hair, (2) moniliform hair, (3) simple multiseriate hair and (4) shaggy hair, have been recognized mostly on the basis of their structural differences. In the past, these types have not been observed in any species of Parthenium studied so far. Out of these four, two types i.e. cylindrical and moniliform hairs are known to occur in the Compositae and remaining two i.e. simple multiseriate and shaggy hairs are the new forms for the family and have been observed for the first time in presently investigated species. Trichomes are an important taxonomic tool in distinguishing between genera and species. Trichomes of the different species of Parthenium as noticed from their structure are useful in distinguishing these species and even their corresponding organs. |
