Comparative leaf anatomy of Iranian Phlomoides (Lamiaceae)

Abstract

Phlomoides (Lamiaceae: Lamioideae) is a species rich, widespread, and taxonomically complex genus. A comparative anatomical study of the petioles and leaf lamina of 17 Phlomoides taxa representing 4 sections of the genus distributed in Iran was carried out to evaluate interspecific relationships and anatomical features that may be useful in species identification and subgeneric classification. The general leaf anatomy of Phlomoides species presented here corroborates earlier studies in Lamiaceae and on a few studied species in the genus. Leaf anatomy provides valuable characters that are useful in subgeneric classification as well as species discrimination in Phlomoides. The most important diagnostic characters are as follows: the shape of transverse section, length of ventral and dorsiventral axis, number of median bundles in the petiole, number of cell layers of palisade and spongy parenchyma, type and thickness of collenchyma as well as trichome type. Based on the present study and in accordance with previous works, some large sections such as Eremostachys appears to be natural, while circumscription of sect. Filipendula should be revised.

Keywords

• Iran
• Leaf anatomy Phlomoides
• Phlomideae
• Lamiaceae