Glandular Hair Formation in Origanum Species

Eleven Origanum species were investigated in this study. Inall these species, leaf glandular hairs have the same structureand they have been found to follow a common developmental pattern.They originate from a single protodermal cell which dividessuccessively parallel to leaf surface to give rise to the footcell, the stalk cell and the mother cell of the head. The latterundergoes a series of symmetric and asymmetric anticlinal divisionsresulting in a 12-celled head (four small cells in the centreand eight large cells peripherally arranged). Determinationof the glandular scale morphology within the Lamiaceae generaand further comparison between the various gland types wouldbe helpful to systematics. Origanum species, Lamiaceae, glandular hair, development