GLANDULAR HAIR FORMATION IN ORIGANUM SPECIES

Eleven Origanum spp. were investigated in this study: [O. heracleoticum, O. onites, O. vulgare, O. majorana, O. dubium, O. microphyllum, O. dictamnus, O. tournefortii, O. scabrum ssp. pulchrum, O. scabrum ssp. scabrum, O. lirium]. In all spp., leaf glandular hairs have the same structure and follow a common developmental pattern. They originate from a single protodermal cell which divides successively parallel to the leaf surface to form the foot cell, the stalk cell and the mother cell of the head. The latter undergoes a series of symmetric and asymmetric anticlinal divisions resulting in a 12-celled head (4 small cells in the center and 8 large cells peripherally arranged). Determination of the glandular scale morphology within the Lamiaceae genera and further comparison between the various gland types would be helpful to systematics.