# Complex Floral Scent Profile of _Neottia ovata_ (Orchidaceae): General Attractants and Beyond
## 4 Discussion  
Our results document that the floral scent bouquet of the generalist-pollination-strategy orchid _Neottia ovata_ is more complex than previously reported. We found 100 floral volatile compounds, of which 99 were identified, with monoterpenes, aliphatic aldehydes, and aliphatic alcohols being the most abundant. [PERSON] [26] found 24 chemical compounds in the Swedish population of this species, of which 17 were identified, with over 90% being monoterpenes and sesquiterpenes, among which linalool and trans-\(\beta\)-ocimene were the most abundant. The recent work of [PERSON] et al. [45] on the _N. ovata_ flower scent documents 21 volatile compounds, mainly alkanes such as heptadecane and pentadecane. Beyond intraspecific differences, those considerable variances in the scent composition between cited and presented data may result from methodological differences. [PERSON] [26] extracted compounds from adsorbents with pentan and diethyl ether using the adsorption-extraction collecting method and GC-MS technique. [PERSON] et al. [45] used SPME fibers with the DVB/CAR/PDMS stationary phase, as we did. However, the exposition time in the headspace gas phase differed, being 24 h in their case, in contrast to the 30 min exposition time we used. Referring to these results, [PERSON] et al. [14] emphasize that controlling sampling parameters, e.g., exposition time, is crucial for optimal analytical results. Specifically, the same authors define the equilibration between the SPME fiber and the volatile sample as lasting a few minutes to half an hour, depending on the compound's volatility and polarity and the adsorbent's properties. As mentioned above, among the identified floral volatiles, monoterpenes, aliphatic aldehydes, and alcohols were present in the highest proportions, while the content of alkanes did not exceed 10% of the TIC. This contrasts with the work of [PERSON] et al. [45], where alkanes constituted the dominant fraction. Among the reviewed orchids, using the SPME technique to adsorb floral volatile compounds was still rare. However, an increase in the richness of compounds in the profiles obtained using this method is noticeable. Besides the methodology used, various environmental factors (geography, habitat, climate) influence flower scent composition [19; 20; 21; 22; 47]. Despite the methodological differences, the available data on the scent of _N. ovata_ flowers, gathered from several sources, provide a comprehensive and nuanced picture of the volatile blends emitted by this species' flowers. With certainty, improving the sampling methods, especially connected with headspace sampling that captures volatile compounds from the air surrounding flowers, was the breakthrough [9; 14; 48]. Volatiles are enriched on the sorbent covering SPME fiber, which allows the detection of even low-abundance compounds from low-emitting flowers, of which _N. ovata_ is a type [14]. The low availability of orchid flowers and the low abundance of semiochemicals are two of the most critical limitations in analyzing orchid fragrances. The spectrum of volatile compounds emitted by _N. ovata_ flowers creates a complex scent profile. It stands out with a relatively diverse pool of compounds and constant biochemical composition. The complex biochemical composition is resolved as an adaptation to a diverse group of potential pollinators [49]. Meanwhile, relative homogeneity acts as an advertisement for a high-quality reward or a reward with unique properties (proportions of sugars and amino acids) that make such a source desirable to flower visitors [50]. These features refer to a generalized pollination system and reproductive assurance strategy within a variable and unpredictable pollinator community [51; 52]. The scent of _N. ovata_ is described as sweet and related to aromatic constituents of the nectar, which is rich in glucose, fructose, and amino acids [30].