Leaflet trichome micromorphology in the Dolentes-Brevipedes taxonomic complex (Mimosa L., Mimosoideae)

Abstract

Here, we studied leaflets of 18 taxa of the Dolentes-Brevipedes taxonomic complex, focusing on micromorphology, type, shape and density of trichomes. Within the non-glandular trichomes, we described three types of non-branched and two types of branched trichomes. We also described two types of stalked glandular trichomes, extending the recent classifications of trichomes in Mimosa. Multiseriate trichomes with lateral projections, which resemble incipient branching, are described here for many taxa. Most studied taxa have pubescent leaflets and show great variability in trichome density values. We also found three different types of blade margins with variation in type, alignment and orientation of trichomes. Results show that the micromorphology of blade trichomes allows distinguishing groups of taxa in this complex, and it could be a new tool for performing a new taxonomic treatment of both subseries.