Studies on the Trichomes of some Compositae I. General Structure

Seventy two Compositae belonging to 56 genera representing the thirteen tribes of the family have been investigated in this study, Trichomes are recognised broadly into two categories namely the 'vegetative' and the 'floral' ones. It is the former that have been presently taken up for detailed investigations. In all 35 trichome types are found so far in the family. Of these, 15 have been described by previous workers which the present author has also observed in the species under investigation. Another 13 are the newly established types by the author. The remaining 7 represent types which the author has not come across during the present investigations but are described in the literature.

The general features of the trichomes in the family are discussed in the light of the present study. The trichomes are shown to exhibit in all four patterns in their structure which provide important evidence in the phylogeny of the trichomes.