## 2 Results and Discussion  
### Volatiles Present in Calypogeia suecica  
Fifty _Calypogeia suecica_ samples were tested for their content of volatile organic compounds (VOCs). Twenty-five samples were collected in 2021 (Table S1a-e) and twenty-five in 2022 (Table S2a-e). Due to the observed differences in the composition of volatile organic compounds, the samples were divided into two groups. The first group included 32 samples (CSU1-1-CSU1-32), while the second group included 18 samples (CSU2-1-CSU2-18). One hundred and seven volatile compounds were detected in the biological material tested. Thirty-eight compounds were identified. The proportion of compounds identified in the first group ranged from 57.21% to 72.56%. However, in the case of the second group, the proportion of identified compounds ranged from 20.03% to 32.06%. Compounds that could not be identified were described using three characteristic ions: a molecular ion and two ions with the highest intensity. Based on the GC-MS analysis, it was found that the dominant groups of compounds in the tested plant material were sesquiterpenes and sesquiterpenoids. Sesquiterpenoids were represented by bisabola-2,10-dien [1,9]oxide (**80**) and 4,5-dehydroviridiflorole (**73**). In the first group, these compounds constituted from 26.25 to 48.24% of the composition of the identified compounds. In the second group, identified sesquiterpenoids constituted only from 2.26% to 5.61% of the composition. However, in the second group, there were compounds with retention indexes of 1532 (**66**) and 1594 (**79**) in amounts ranging from 9.69% to 18.21% and 8.81% to 19.84%, respectively. MS spectra suggested that these compounds belonged to the sesquiterpenoid classification. It should be noted that the presence of these compounds was not detected in the first group. In the case of the first group, sesquiterpenes were present at levels ranging from 17.78% to 34.77%. However, in the case of the second group, these compounds occurred at a rate of 14.39% to 24.88%. \(\gamma\)-curcumene (**53**) was the dominant sesquiterpene in the first group. It occurred at levels from 1.27% to 7.73%. In the case of the second group, the dominant sesquiterpene was \(\gamma\)-bisabolene (**60**). It was marked in the second group at a level from 4.17% to 8.74%. Bicyclogermacrene (**58**) is a sesquiterpene that was present at similar levels in groups one and two. In the case of the first group, its prevalence ranged from 1.07% to 6.48%. In the case of the second group, it ranged from 1.03% to 6.11%. A similar situation occurred with another sesquiterpene, anastreptene (**32**). In the case of the first group, its occurrence ranged from 4.60% to 9.53%. In the case of the second group, it ranged from 3.06% to 6.45%. Conversely, \(\alpha\)-zingiberene (**57**) is a sesquiterpene that occurred in the first group at levels from 0.09% to 1.32%, and its presence was not detected in the second group. Other compounds belonging to the sesquiterpene group that were identified in the tested plant material included \(\delta\)-elemene (**30**), \(\alpha\)-funebrene (**33**), \(\beta\)-elemene (**34**), 7-epi-sesquithujene (**35**), italicene (**36**), 9-aristolene (**37**), 1(10),8-aristoladiene (**38**), \(\beta\)-barbateate (**46**), \(\alpha\)-curcumene (**55**) and \(\beta\)-sesquiphellandrene (**64**). Compounds belonging to the group of monoterpenes were also identified in the analyzed plant material, such as tricylene (**6**), \(\alpha\)-pinene (**7**), and \(\beta\)-pinene (**10**). Monoterpenoids include compounds such as bornyl acetate (**26**) and isobornyl acetate (**27**). However, in the case of both monoterpenes and terpenoids, the detected amounts in the studied samples were small. Monoterpenes were present in amounts of 0.02% to 0.07% in the first group, and in the second group, 0.03% to 0.17%. Monoterpenoids occurred in the first group at levels from 0.00 to 0.08%, and in the second group from 0.00% to 0.30%.