This study investigates the phylogenetic relationships, taxonomic
status, and morphometric analysis of 21 naturally occurring taxa of the
Acer genus in Turkey. A comparative analysis was conducted using
18 informative morphometric characters and DNA sequence data from the
cpDNA ndhF, trnL-F, and nrDNA ITS gene regions. To date, there
has been no comprehensive molecular and morphometric study conducted on
the genus in Turkey. Factor Analysis of Mixed Data (FAMD) was performed
on selected morphometric traits, revealing highly distinctive
characteristics for the Acer genus at the series, sectional, species,
and sub-species levels, including Dim1 traits such as leaf
length, leaf width, petiole length, loculus length, loculus width, fruit
wing length, and fruit length, as well as Dim2 traits such as
pubescence of leaf beneath, margin, latex, and form of nutlets, along
with inflorescence, bud, and shoot features. The nuclear ITS and
chloroplast trnL-F gene regions also exhibited significant
diversity and provided valuable information. Phylogenetically,
Acer species in Turkey showed close relationships with species
native to the Eurosiberian phytogeography. The results of the
phylogenetic and morphometric analyses offered reliable taxonomic
clarifications for the first time, specifically for the species
Acer tauricolum, A. divergens (endemic to Turkey), A.
orthocampestre, and A. cappadocicum subsp. cappadocicum.
The chloroplast lineage of Acer species native to Turkey appears
to have originated in the late Oligocene and experienced significant
diversification during the Miocene. The majority of Acer
phylogenetic positions in Turkey are likely influenced by the habitats
created by the northern mountain ranges.