Pericarp Ultrastructure of Salvia Section Hemisphace (Mentheae; Nepetoideae; Lamiaceae)

The genus Salvia L. (sage), which belongs to the tribe Mentheae of the subfamily Nepetoideae within the family Lamiaceae, is well-known for its medicinal, ornamental, culinary and hallucinogenic uses. The section Hemisphace Benth. of this genus is respresented in Turkey by three species. The present study is conducted on two morphologically similar Salvia species belonging to this section: Salvia napifolia Jacq. and S. russellii Benth. (excluding S. verticillata L.). For this purpose, the pericarp ultrastructure of these species is investigated in detail with the help of light and transmission electron microscopy (TEM). Morphometric characters are analyzed using one-way Analysis of Variance (ANOVA) with Tukey’s honestly significant difference (HSD) post-hoc test for multiple comparisons. The taxonomic potential of pericarp characteristics is discussed. The most prominent traits are the thickness of the pericarp, mesocarp and sclerenchyma region that permit the separation of the species studied. Myxocarpy (mucilage formation) is recognized on the surface of the wetted mericarps of both species. Mucilaginous cells reveal a moderate reaction but S. napifolia is of a somewhat thicker mucilaginous layer, about 0.20-0.34 mm. This study represents the first comprehensive findings on the pericarp ultrastructure of the species examined