Article

The study consists in a micromorphological investigation of the characteristic trichome types in leaves, stems, calyces and corollas in the Stachys L. species (Stachys cretica L. subsp. vacillans Rech. f., Stachys ehrenbergii Boiss., Stachys distans Benth., Stachys neurocalycina Boiss., Stachys nivea Labill., Stachys palaestina L.) distributed in Lebanon and restricted to Levantine as part of the taxonomical study of the genus _Stachys. The results showed twenty one different types of trichomes (11 non-glandular, 10 glandular) on the studied species. Fourteen types were characteristic for one species alone. Only four types of trichomes were found on all the 6 studied species. Of the 21 different types of trichomes, 8 non-glandular hairs and six glandular hairs were characteristic of one species. Those results indicate that non-glandular hairs are more important than glandular hairs concerning the separation between Stachys species. In addition, the study shows that the corollas and calyces of the studied species have the most important number of typical trichomes (6 of 21). Concerning the species Stachys neurocalycina comes first with five typical trichomes (1, 2, 4, 5 and 17), followed by Stachys palaestina with four (14, 15, 20 and 21), Stachys ehrenbergii with two (12 and 13), and one typical trichome for Stachys cretica subsp. vacillans (19), Stachys distans (18) and Stachys nivea (7).