Trichome types, foliar indumentum, and epicuticular wax in the Mediterranean ‘Gall Oaks’, Quercus subsectio Galliferae (Spach) Guerke (Fagaceae): implications for taxonomy, ecology, and evolution
(English)Manuscript (preprint) (Other academic)
Trichome characters are often considered taxonomically important in oak species. Here, we investigated a group of Mediterranean oaks, Quercus subsectio Galliferae and Q. pubescens, using a large dataset and covering the entire distribution range of the group. Due to different interpretations of terms in previous studies, trichome terminology was re-assessed aiming at a practicable nomenclature. In contrast to previous studies, we found that acicular, bifurcate, fasciculate, stellate, uniseriate and capitate trichomes are represented in all taxa. One exception is the lack of bifurcate trichomes in Quercus canariensis. This suggests that seemingly taxonomically informative presence/absence data for trichome types as reported previously may be a result of too small sample size and hence unrepresentative. In combination with other morphological characters (leaf shape, size and texture), features of the indumentum, such as the floccose, easily removable trichomes in Quercus canariensis can be important in species delimitation. Making use of trichome characteristics in Quercus subsectio Galliferae requires exhaustive sampling of all taxa in order to extract reproducible taxonomic signal from quantitative characters. This would be the prerequisite for building datasets that could be used for phylogenetic studies, investigations of character evolution and comparative morphological studies.
Quercus, trichomes, trichome classification, foliar indumentum, epicuticular wax, taxonomy, ecological significance, evolution
Research subject Plant Ecology; Plant Morphology; Plant Systematics
IdentifiersURN: urn:nbn:se:su:diva-62715OAI: oai:DiVA.org:su-62715DiVA: diva2:444095