Nutlet micromorphology and its systematic implications in Phlomoides Moench

Nutlets of 20 taxa of Phlomoides, representing mostly the currently recognized sections were examined by scanning electron microscopy. The basic shape of nutlets in most taxa studied is broadly ovate, but ovate, triangular and oblong can also be found in few species. Regarding sculpturing pattern of nutlet surface four basic types can be distinguished: reticulate, scalariform, ruminate and rugose. The reticulate type is the most common among the studied species, but the variation in alignment, size, and shape of its composing cells provide further evidence that is useful as diagnostic characteristics. However, the type of sculpturing is more useful for separating species within the sections, rather than correlating the related ones to each other. For example, in sect. Filipendula shows four different types of sculpturing. However, nutlet microsculpturing is not useful in separating large natural groups like sections in this genus. It seems also that contrary to other genera of Lamiaceae, nutlet characters are of low phylogenetic value in this genus

کلیدواژه ها:

Phlomoides ، Nutlet morphology ، Taxonomy ، Classification ، Phlomideae