Comparative morphological studies on achene of some taxa of asteraceae

الملخص EN

Morphological structure and different characters of achene is most important from the taxonomic point of view.

In present study achene shape, colour, size, texture and pappus type were recorded for 20 taxa of Asteraceae by using light microscope (LM) and scanning electron microscope (SEM).

Examination of pappus by SEM recorded 6 groups; (1- Scarbous barbellate fine bristles and scarbous barbellate bristles, 2- Scarbous subulate scales free, 3- Scarious scales, 4- Paleaceous scales corona, 5- Plumose bristles and 6- Capillary barbellate).

Also eight patterns were recognized based on surface sculpturing pattern: reticulate, with two subtypes, tuberculate, sulcate, puncticulate, colliculate, aculeate, lineate and striate.

The data proved useful in the construction of a dichotomous indented key to the studied taxa.

Twenty-two characters with 85 characters stats were used to generate anatomical key using the DELTA key-generating programs.