4. DISCUSSION
The morphological structures of the achenes offer important data in
connection with evolutionary relationships of the flowering plants
(Corner, 1976; Karaismailoğlu, 2015). Achene morphological
characteristics have so far been comprehensively performed to elucidate
inter-species relatives within various genera of the family Asteraceae
(Karaismailoğlu, 2015; Şirin et al., 2017; Ghimire et al., 2018; Bona,
2020; Bona et al., 2023). This is the first investigation to display the
morphological features and elemental contents of the achenes of TurkishArtemisia , and it could be a pioneering work for next studies in
many related genera.
The macro-morphological characters of the achenes reveal variances among
the examined Artemisia taxa (Figure 1 and Table 2). The taxa
examined in our study are very different with regard to achene color.
Light brown-brown dominates in the genus, whereas brown-dark brown,
straw yellowish-light brown, dark brown and dark brown-blackish brown
have a distinctive character among taxa by having a small number of
taxa. Artemisia annua (ovate) and A. tournefortiana(fusiform-oblong) taxa are more or less similar in terms of the
population appearance and flower structures, but they can be basically
distinguished with relating of achene shape.
The investigates containing surface micro-morphological features of the
fruits in various plant families such as Asteraceae, Umbelliferae,
Chenopodiaceae, Boraginaceae, Scrophulariaceae, Brassicaceae, Lamiaceae,
Solanaceae offer taxonomically valuable information (Juan et al., 2000;
Özcan, 2004; Karcz et al., 2005; Binzet & Akçin, 2009; Kaya et al.,
2011; Karaismailoğlu, 2015b; Khafagi et al., 2018; Karaismailoğlu &
Güner, 2019). Also, the significance and usefulness of SEM in solving of
taxonomic problems and in describing of taxa have been emphasized by
many researchers (Heywood, 1971; Karaismailoğlu & Erol, 2018; Eroğlu et
al., 2022). However, there are few studies on the importance of achene
micromorphology in the genus Artemisia (Boyko, 2013; Abdel-Hamid,
2020; Vakulenko et al., 2020; Al‑Ajmi et al., 2021). In this study,
Turkish Artemisia taxa have been examined for the first time. We
determined ten types of achene surface ornamentation in this study. In
the genus, the most common achene ornamentation type is irregularly or
regularly sulcate. Contrary to this study, reticulate or
reticulate-areolate surface ornamentation types have been commonly
encountered among species from many angiosperm families (Erol et al.,
2006; Karaismailoğlu, 2015a; Özbek et al., 2018; Karaismailoğlu & Erol,
2018; Eroğlu et al., 2021; Eroğlu et al., 2022). The ruminate (inA. abrotanum ), rugose (in A. chamaemelifolia ), favulariate
(in A. arborescens ), alveolate (in A. santonicum subsp.patens ), tuberculate (in A. taurica var. vanensis )
and reticulate (in A. bashkalensis ) ornamentation types are taxon
specific. Moreover, ornamentation types facilitate the separation of
closely correlated taxa like A. annua(sulcate-scalariform)-A.
tournefortiana (irregularly sulcate), A. alpina(sulcate-scalariform)- A. splendens (irregularly sulcate),A. santonicum subsp. santonicum(sulcate-scalariform)-A. santonicum subsp. patens(alveolate) and A. taurica var. taurica (irregularly
sulcate)- A. taurica var. vanensis (tuberculate) taxa
(Figure 2 and Table 3). Also, previous seed or fruit surface
examinations have displayed that the types and arrangements of the
anticlinal and periclinal cell walls are diagnostic features in the
formation of inter-taxa relations (Barthlott, 1981; Karaismailoğlu et
al., 2018; Özbek et al., 2018; Eroğlu et al., 2022). The kinds of
anticlinal and periclinal cell walls, and epidermal cell forms of the
examined taxa disclose differences among taxa. The macro and
micro-morphological results of this search are separated all taxa
studied from each other, and they are consistent with the previous works
including the exomorphic characters of achenes of the family Asteraceae
(Karaismailoğlu, 2015; Coşkunçelebi et al., 2016; Şirin et al., 2017;
Özbek et al., 2018; Bona, 2020; Ayaz et al., 2020; Vakulenko et al.,
2020; Bona et al., 2023).
The elemental data of the examined taxa show that the achene samples are
composed of over 77% C and a lesser amount of Mg, Cl, Si, Na and S. The
distribution of elements in each achene is given in Table 4. The amounts
of elements present have showed considerable variation among the taxa
studied. A. austriaca contains more than 5 times more Ca element
than the average of other studied taxa. Elements or percentage of
elements contained by closely related taxa are different, for exampleA. annua (C, Ca and K)-A. tournefortiana (C, Ca, K, Mg, Cl
and Si), A. alpina (C, Ca and K)-A. splendens (C, Ca, K,
Mg and Cl), and A. taurica var. taurica (C, Ca and K
)-A. taurica var. vanensis (C, Ca, K, Mg and Cl) taxa
(Table 4). A. alpina species is also distinguished from the
others by having the S element among the studied taxa. In general,
achene elemental content or frequency varies in all studied taxa.
A dendrogram has been formed to assess the morphological characters of
the achenes of Turkish Artemisia taxa with UPGMA cluster analysis
(Figure 3). The dendrogram, showing 2 major groups, is partially
suitable with the consequences of Cullen (1975), Davis (1975) and Davis
et al. (1988). As stated by the descriptions in the Flora of Turkey, the
taxonomic closeness in the A. annua -A. tournefortiana ,A. alpina -A. splendens , A. santonicum subsp.santonicum -A. santonicum subsp. patens and A.
taurica var. taurica -A. taurica var. vanensis taxa
is somewhat conserved. On the other hand, a logical relationship could
not be established in determining the section boundaries (Figures. 3-4
and Table 5). Moreover, A. vulgaris has been defined as an
isolated species with a very dissimilar description as a consequence of
its unique leaf features within the genus in the Flora of Turkey. This
species has exhibited parallel characters in the dendrogram formed
according to achene morphological features, and consisted of a clade
apart from two major groups.