The taxonomic utility of floral microcharacters in Lepidaploa (Vernonieae: Asteraceae)
2 May 2018Marques, Danilo; Angulo, Maria; Nakajima, Jimi; Dematteis, Massimiliano
Lepidaploa belongs to tribe Vernonieae, one of the most complex tribes of Asteraceae, and relationships among Lepidaploa and related genera are poorly understood. Microcharacters may be of taxonomic value and used in the identification of different taxonomic categories. The morphology of phyllaries, florets and cypselae was analysed in detail for the first time in 23 species of Lepidaploa to evaluate the reliability of microcharacters as taxonomic markers. The results were also discussed in relation to closely related genera of the Vernonieae. The species were studied using stereo, light, and scanning electron microscopy. Eight trichome types (non–glandular and glandular) were observed on phyllaries, florets and cypselae. This study demonstrates that the ocurrence in different combinations of trichome types and crystals, presence of stylar basal node, idioblasts and glandular apical anther appendages are taxonomically important to differentiate between related species of Lepidaploa. However, they are of little utility to distinguish between closely related genera of Vernonieae.