# Complex Floral Scent Profile of _Neottia ovata_ (Orchidaceae): General Attractants and Beyond
## 4 Discussion
Moreover, the importance of scent as an attractant is also emphasized by the anatomical characteristics of flowers closely related to the emission of volatile compounds [35]. We did not investigate the intraspecific variability of the _N. ovata_ flower scent, while the profiles ofindividuals deriving from three different localities showed repeatability. Almost 70% of compounds appear in more than two analyzed samples, and the components that most differentiate the samples occur with the lowest abundance (<1% TIC). Regardless of the method used, when we considered flower volatiles of orchid species, both the nectar-rewarding and food-deceptive, the generalist and specialist ones, about 10% of components occurred frequently (in 5-10 of the species). Approximately 50-60% of compounds were found only in the scent of a single species, which can be linked both to the specificity of the species and the extraction method used. The most frequently recurring floral scent compounds are terpenes and aromatic compounds (benzenoids), known for their biological activity and as general attractants that initiate a response in various flower visitors [9; 10]. It should be emphasized that the floral scent is a blend of components with synergistic effects, of which we still know very little. Only the behavioral and electrophysiological experiments (EAD) allow for evaluating the biological activity of specific flower fragrance components. However, they are still limited, in orchids, primarily to sexually deceptive pollination systems, where the scent profile is often poor, with one or two active components [53; 54; 55]. Within those universal, general scent attractants, terpenes are among the most important groups, primary in character, associated with repelling floriferous animals and antibacterial and antifungal activity [56]. From this biochemical group, linalool is one of the most abundant components of the _N. ovata_ scent bouquet, as reported by [PERSON] [26], and also the most essential and repetitive general scent attractant, luring different groups of pollinators [9]. This acyclic monoterene has been confirmed to be active as a long-distance attractant and is connected with the fragrance emitted by nectar [50; 57]. Linalool was also considered in pollination systems, where bee pollinators search for a perfume reward, but rather as a long-distance decoy [58]. In turn, [PERSON] et al. [50] reveal that _Bombus impatiens_ could detect the differences in linalool emission by flowers and choose those with a higher rate. In general, the quality of scent, including terpene concentration--mainly linalool, limonene, and \(\beta\)-pinene--serves as a signal for pollinators to identify the floral stage and presence of nectar [56; 59]. Simultaneously, linalool is almost absent in the fragrance composition of orchid flowers that exhibit specialized pollination systems [60], which may significantly limit the number of insect visits, especially of general pollinators. Another monoterpene found among compared orchids, with a general scent character, is \(\alpha\)-pinene, one of the significant aphid alarm pheromones that attract horwerfly females [61]. The monoterenes \(\alpha\)-pinene and \(\beta\)-pinene, with appropriately huge concentrations, have elicited a response to flowers from _Bombus terrestris_[62]. Another bicyclic monoterpene, sabinene, is found among flower volatiles of _N. ovata_ and in almost half of the analyzed orchids' flower scent profiles. This compound contributes to spicy, citrusy, and piney aromas that are detectable by the human senses. Furthermore, among orchids, sabinene is found in euglossophilous orchid flowers, which together with pinene, limonene, and \(\alpha\)-terpineol forms the final fragrance combination, which is attractive to bees searching for perfume reward [60]. Activity connected with insect pheromones was also defined for mycrene and \(\beta\)-phellandrene [61], commonly found components of different orchid flower scents.