Fragrant Volatile Compounds in the Liverwort Drepanolejeunea madagascariensis (Steph.) Grolle: Approach by the HS‐SPME Technique

Three populations of the epiphyllous liverwort Drepanolejeunea madagascariensis collected in the cloud forests of Reunion Island (Mascarene Archipelago) were investigated for their volatile compounds, because of the pleasant, sweet, warm, woody‐spicy, and herbaceous fragrance, slightly reminiscent of dill, of this species. By applying the headspace solid‐phase microextraction (HS‐SPME) technique coupled to GC/MS analysis, 34 compounds were detected in total, with p‐menth‐1‐en‐9‐ol (28.8–43.5%), limonene (10.5–14.7%), β‐phellandrene (8.8–11.6%), and the so‐called dill ether (8.5–16.6%) as the main components. The presence of 1‐epi‐α‐pinguisene confirms the possible use of pinguisane‐type sesquiterpenoids as a characteristic chemical marker for the order Jungermanniales.     

Chemical Composition of Juniperus communis L. Cone Essential Oil and Its Variability among Wild Populations in Kosovo

Ripe cones of Juniperus communis L. (Cupressaceae) were collected from five wild populations in Kosovo, with the aim of investigating the chemical composition and natural variation of essential oils between and within wild populations. Ripe cones were collected, air dried, crushed, and the essential oils obtained by hydrodistillation. The essential‐oil constituents were identified by GC‐FID and GC/MS analyses. The yield of essential oil differed depending on the population origins and ranged from 0.4 to 3.8% (v/w, based on the dry weight). In total, 42 compounds were identified in the essential oils of all populations. The principal components of the cone‐essential oils were α‐pinene, followed by β‐myrcene, sabinene, and D ‐limonene. Taking into consideration the yield and chemical composition, the essential oil originating from various collection sites in Kosovo fulfilled the minimum requirements for J. communis essential oils of the European Pharmacopoeia. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to determine the influence of the geographical variations on the essential‐oil composition. These statistical analyses suggested that the clustering of populations was not related to their geographic location, but rather appeared to be linked to local selective forces acting on the chemotype diversity.     

Chemical Variability of the Needle Oil of Juniperus communis ssp. alpina from Corsica

The composition of 109 samples of essential oil isolated from the needles of Juniperus communis ssp. alpina growing wild in Corsica was investigated by GC (in combination with retention indices), GC/MS, and ¹³C‐NMR. Forty‐four compounds accounting for 86.7–96.7% of the oil were identified. The oils consisted mainly of monoterpene hydrocarbons, in particular, limonene (9.2–53.9%), β‐phellandrene (3.7–25.2%), α‐pinene (1.4–33.7%), and sabinene (0.1–33.6%). The 109 oil compositions were submitted to k‐means partitioning and principal component analysis, which allowed the distinction of two groups within the oil samples. The composition of the major group (92% of the samples) was dominated by limonene and β‐phellandrene, while the second group contained mainly sabinene beside limonene and β‐phellandrene.     

Biogeographic Variation of Foliar n‐Alkanes of Juniperus communis var. saxatilis Pallas from the Balkans

The composition of the epicuticular n‐alkanes isolated from the leaves of ten populations of Juniperus communis L. var. saxatilis Pallas from central (continental) and western (coastal) areas of the Balkan Peninsula was characterized by GC‐FID and GC/MS analyses. In the leaf waxes, 14 n‐alkane homologues with chain‐lengths ranging from C₂₂ to C₃₅ were identified. All samples were dominated by n‐tritriacontane (C₃₃), but differences in two other dominant n‐alkanes allowed separating the coastal from the continental populations. Several statistical methods (ANOVA, principal component, discriminant, and cluster analyses as well as the Mantel test) were deployed to analyze the diversity and variability of the epicuticular‐leaf‐n‐alkane patterns of the ten natural populations of J. communis var. saxatilis and their relation to different geographic and bioclimatic parameters. Cluster analysis showed a high correlation of the leaf‐n‐alkane patterns with the geographical distribution of the investigated samples, differentiating the coastal from the continental populations of this taxon. Several bioclimatic parameters related to aridity were highly correlated with this differentiation.     

Chemical Variability of Algerian Myrtus communis L.

The composition of 55 samples of essential oil isolated from the aerial parts of wild growing Myrtus communis L. harvested in 16 locations from East to West Algeria were investigated by GC (determination of retention indices) and ¹³C‐NMR analyses. The essential oils consisted mainly of monoterpenes, α‐pinene (27.4–59.2%) and 1,8‐cineole (6.1–34.3%) being the major components. They were also characterized by the absence of myrtenyl acetate. The compositions of the 55 oils were submitted to k‐means partitioning and principal component analysis, which allowed the distinction of two groups within the oil samples, which could be subdivided into two subgroups each. Groups I (78% of the samples) and II were differentiated on the basis of the contents of α‐pinene, linalool, and linalyl acetate. Subgroups IA and IB could be distinguished by their contents of α‐pinene and 1,8‐cineole. Subgroups IIA and IIB differed substantially in their contents of 1,8‐cineole and limonene. All the samples contained 3,3,5,5,8,8‐hexamethyl‐7‐oxabicyclo[4.3.0]non‐1(6)‐ene‐2,4‐dione (up to 4.9%).     

Pollen Diversity and Volatile Variability of Honey from Corsican Anthyllis hermanniae L. Habitat

Melissopalynological, physicochemical, and volatile analyses of 29 samples of Corsican ‘summer maquis’ honey were performed. The pollen spectrum was characterized by a wide diversity of nectariferous and/or polleniferous taxa. The most important were Anthyllis hermanniae and Rubus sp., associated with some endemic taxa. Castanea sativa was also determined in these honeys with a great variation. The volatile fraction was characterized by 37 compounds and dominated by phenolic aldehydes and linear acids. The major compounds were phenylacetaldehyde, benzaldehyde, and nonanoic acid. Statistical analysis of pollen and volatile data showed that 18 samples were characterized by a high abundance of phenylacetaldehyde, which might relate to the high amount of A. hermanniae and Rubus sp. Eleven other samples displayed a higher proportion of phenolic ketones and linear acids, which characterized the nectar contribution of C. sativa and Thymus herba‐barona, respectively.     

The Volatile Profiles of a Rare Apple (Malus domestica Borkh.) Honey: Shikimic Acid‐Pathway Derivatives,Terpenes, and Others

The volatile profiles of rare Malus domestica Borkh . honey were investigated for the first time. Two representative samples from Poland (sample I) and Spain (sample II) were selected by pollen analysis (44–45% of Malus spp. pollen) and investigated by GC/FID/MS after headspace solid‐phase microextraction (HS‐SPME) and ultrasonic solvent extraction (USE). The apple honey is characterized by high percentage of shikimic acid‐pathway derivatives, as well as terpenes, norisoprenoids, and some other compounds such as coumaran and methyl 1H‐indole‐3‐acetate. The main compounds of the honey headspace were (sample I; sample II): benzaldehyde (9.4%; 32.1%), benzyl alcohol (0.3%; 14.4%), hotrienol (26.0%, 6.2%), and lilac aldehyde isomers (26.3%; 1.7%), but only Spanish sample contained car‐2‐en‐4‐one (10.2%). CH₂Cl₂ and pentane/Et₂O 1 : 2 (v/v) were used for USE. The most relevant compounds identified in the extracts were: benzaldehyde (0.9–3.9%), benzoic acid (2.0–11.2%), terpendiol I (0.3–7.4%), coumaran (0.0–2.8%), 2‐phenylacetic acid (2.0–26.4%), methyl syringate (3.9–13.1%), vomifoliol (5.0–31.8%), and methyl 1H‐indole‐3‐acetate (1.9–10.2%). Apple honey contained also benzyl alcohol, 2‐phenylethanol, (E)‐cinnamaldehyde, (E)‐cinnamyl alcohol, eugenol, vanillin, and linalool that have been found previously in apple flowers, thus disclosing similarity of both volatile profiles.     

Chemical Variability of the Essential Oil of Juniperus phoenicea var. turbinata from Algeria

The chemical composition of 50 samples of leaf oil isolated from Algerian Juniperus phoenicea var. turbinata L. harvested in eight locations (littoral zone and highlands) was investigated by GC‐FID (in combination with retention indices), GC/MS, and ¹³C‐NMR analyses. The composition of the J. phoenicea var. turbinata leaf oils was dominated by monoterpenes. Hierarchical cluster and principal component analyses confirmed the chemical variability of the leaf oil of this species. Indeed, three clusters were distinguished on the basis of the α‐pinene, α‐terpinyl acetate, β‐phellandrene, and germacrene D contents. In most oil samples, α‐pinene (30.2–76.7%) was the major compound, associated with β‐phellandrene (up to 22.5%) and α‐terpinyl acetate (up to 13.4%). However, five out of the 50 samples exhibited an atypical composition characterized by the predominance of germacrene D (16.7–22.7%), α‐pinene (15.8–20.4%), and α‐terpinyl acetate (6.1–22.6%).     

Population Variability of Essential Oils of Pinus heldreichii from the Scardo‐Pindic Mountains Ošljak and Galičica

The needle‐terpene profiles of two natural Pinus heldreichii populations from Mts. O?ljak and Gali?ica (Scardo‐Pindic mountain system) were analyzed. Among the 68 detected compounds, 66 were identified. The dominant constituents were germacrene D (28.7%), limonene (27.1%), and α‐pinene (16.2%). β‐Caryophyllene (6.9%), β‐pinene (5.2%), β‐myrcene (2.3%), pimaric acid (2.0%), α‐humulene (1.2%), and seven additional components were found to be present in medium‐to‐high amounts (0.5–10%). Although the general needle‐terpene profile of the population from Gali?ica was similar to those of the populations from Lov?en, Zeletin, Bjelasica, and Zlatibor‐Pe?ter (belonging to the Dinaric Alps), the principle‐component analysis (PCA) of seven terpenes (β‐myrcene, limonene, β‐elemene, β‐caryophyllene, α‐humulene, δ‐cadinene, and germacrene D‐4‐ol) in 121 tree samples suggested a partial divergence in the needle‐terpene profiles between the populations from the Scardo‐Pindic mountain system and the Dinaric Alps. According to previously reported data, the P. heldreichii samples from the Balkan‐Rhodope mountains lack β‐caryophyllene and germacrene D, but contain γ‐muurolene in their terpene profile. Differences in the terpene composition between populations growing in the three above‐mentioned mountain systems were compared and discussed.     

Volatile compounds of Asphodelus microcarpus Salzm. et Viv. Honey obtained by HS-SPME and USE analyzed by GC/MS

Chemical analysis of Asphodelus microcarpus Salzm. et Viv. honey is of great importance, since melissopalynology does not allow the unambiguous determination of its botanical origin. Therefore, the volatile compounds of eight unifloral asphodel honeys have been investigated for the first time. The honey extracts were obtained by headspace solid-phase microextraction (HS-SPME) and ultrasonicsolvent extraction (USE) and analyzed by GC and GC/MS. In the honey headspace, 31 volatile compounds were identified with high percentages of 2-phenylacetaldehyde (2; 14.8–34.7%), followed by somewhat lower percentages of methyl syringate (1; 10.5–11.5%). Compound 2 is not a specific marker of the botanical origin of the honey, but its high percentage can be emphasized as headspace characteristic of asphodel honey. The extraction solvent for all the samples was selected after extracting a representative sample with pentane, Et(2)O, pentane/Et(2)O 1:2 (v/v), and CH(2)Cl(2) . Compound 1 was the major constituent of all the USE extracts (46.8–87.0%). According to these preliminary results, all the honey samples were extracted by USE with the solvent pentane/Et(2)O 1:2. A total of 60 volatile compounds were identified with 1 as predominant compound (69.4–87.0%), pointing out 1 as Asphodelus honey volatile marker.     

Solid-phase microextraction (SPME) analysis of six Italian populations of Ephedra nebrodensis Tineo ex Guss. subsp. nebrodensis

Headspace solid-phase microextraction (HS-SPME) coupled with GC/FID and GC/MS was applied for the first time in the analysis of the volatile fraction of an Ephedra species. Notably, six Italian populations (Marche, Abruzzo, and Sardinia) of Ephedra nebrodensis subsp. nebrodensis, covering almost the entire Italian area, were investigated to examine the chemical variability and to support the taxonomy of the species. A fiber screening with polymethylsiloxane (PDMS), Carboxen(TM) /polymethylsiloxane (CAR/PDMS), and polymethylsiloxane/divinylbenzene (PDMS/DVB) coatings, together with an optimization of the extraction conditions were carried out before analysis of the six populations. A total of 119 volatiles were identified in the headspace of different samples, accounting for 63.35-100.00% of the total volatiles. A great variability was found in the qualitative composition of different samples, since only 18 components were in common among all populations. The headspace composition was dominated by sesquiterpene hydrocarbons (52.30-88.32%), with β-maaliene (traces-7.49%), β-patchoulene (traces-1.29%), β-panasinsene (traces-6.85%), α-isocomene (traces-31.25%), α-trans-bergamotene (traces-6.95%), alloaromadendrene (traces-33.20%), α-acoradiene (traces-9.41%), and γ-muurolene (0.61-16.33%) being the most abundant constituents. Noteworthy is the occurrence in a sample of two major unknown sesquiterpenes, one hydrocarbon (24.49%, RI: 1396) and one oxygenated compound (10.37%, RI: 1591), whose mass spectra were reported for the first time. Multivariate chemometric techniques, such as cluster analysis (CA) and principal component analysis (PCA), were used to characterize the samples according to the geographical origin.     

Variability of the Needle Essential Oils of Juniperus deltoides R.P.Adams from Different Populations in Serbia and Croatia

The essential‐oil compositions of one Croatian and three Serbian populations of Juniperus deltoides R.P.Adams have been determined by GC/MS analysis. In total, 147 compounds were identified, representing 97.3–98.3% of the oil composition. The oils were dominated by monoterpenes, which are characteristic components for the species of the section Juniperus. Two monoterpenes, α‐pinene and limonene, were the dominant constituents, with a summed‐up average content of 49.45%. Statistical methods were used to determine the diversity of the terpene classes and the common terpenes between the newly described J. deltoides populations from Serbia and Croatia. Only reports on several specimens from this species have been reported so far, and there are no studies that treat population diversity. Cluster analysis of the oil contents of 21 terpenes showed high correlation with the geographical distribution of the populations, separating the Croatian from the Serbian populations. The comparison of the essential‐oil compositions obtained in the present study with literature data, showed the separation of J. deltoides and J. oxycedrus ssp. oxycedrus from the western Mediterranean region.     

Leaf n‐Alkanes as Characters Differentiating Coastal and Continental Juniperus deltoides Populations from the Balkan Peninsula

The composition of the cuticular n‐alkanes isolated from the leaves of nine populations of Juniperus deltoides R.P.Adams from continental and coastal areas of the Balkan Peninsula was characterized by GC‐FID and GC/MS analyses. In the leaf waxes, 14 n‐alkane homologues with chain‐lengths ranging from C₂₂ to C₃₅ were identified. n‐Tritriacontane (C₃₃) was dominant in the waxes of all populations, but variations between the populations in the contents of all n‐alkanes were observed. Several statistical methods (ANOVA, principal component, discriminant, and cluster analyses) were used to investigate the diversity and variability of the cuticular‐leaf‐n‐alkane patterns of the nine J. deltoides populations. This is the first report on the n‐alkane composition for this species. The multivariate statistical analyses evidenced a high correlation of the leaf‐n‐alkane pattern with the geographical distribution of the investigated samples, differentiating the coastal from the continental populations of this taxon.     

Volatile components of whole and different plant parts of bastard balm (Melittis melissophyllum L., Lamiaceae) collected in Central Italy and Slovakia

The aim of this work was to trap the volatiles released from whole frozen and dry aerial parts, and, separately, from different organs (leaves, stems, corolla and calyx) of bastard balm (Melittis melissophyllum L., Lamiaceae) populations collected in Italy and Slovakia by HS-SPME, and to identify the headspace constituents responsible for the characteristic aroma impression by GC/FID and GC/MS techniques. Among more than 100 volatile components detected, the C(8) alcohol oct-1-en-3-ol, responsible for the typical mushroom-like odor, and the phenolic coumarin, with a characteristic sweet and creamy vanilla bean odor, played a major role in the aroma of whole aerial parts and different plant organ samples. In particular, dry calyx parts could be proposed as flavoring agent in food products as mushroom aroma enhancer. Multivariate chemometric techniques, such as cluster analysis and principal component analysis, were used to characterize the sample populations according to the geographical origin and processing of plant material.     

Pollen aroma fingerprint of two sunflower (Helianthus annuus L.) genotypes characterized by different pollen colors

Samples of fresh pollen grains, collected from capitula in full bloom from two genotypes of sunflower (Helianthus annuus L.) and characterized by a different color, i.e., white‐cream (WC) and orange (O), were analyzed by the HS‐SPME (headspace solid phase microextraction)/GC/MS technique. This study defined for the first time the fingerprint of the sunflower pollen, separated from the disc flowers, to define its contribution to the inflorescence aroma. In the GC/MS fingerprints of the WC and O genotypes, 61 and 62 volatile compounds were identified, respectively. Monoterpene hydrocarbons (34% in O vs. 28% in WC) and sesquiterpene hydrocarbons (37% in O vs. 31% in WC) were ubiquitous in all samples analyzed and represented the main chemical classes. α‐Pinene (21% in O vs. 20% in WC) and sabinene (11% in O vs. 6% in WC) were the dominant volatiles, but also a full range of aliphatic hydrocarbons and their oxygenated derivatives gave a decisive contribution to the aroma composition (10% in O vs. 12% in WC). In addition, dendrolasin (3% in O vs. 4% in WC) and some minor constituents such as (E)‐hex‐2‐en‐1‐ol (0.4% in O vs. 0.1% in WC) were pointed out not only for their contribution to the pollen scent, but also for their well‐known role in the plant ecological relationships. Having evaluated two pollen morphs with different carotenoid‐based colors, the study sought to highlight also the presence of some volatile precursors or derivatives of these pigments in the aroma. However, the pollen aroma of the two selected genotypes made a specific chemical contribution to the sunflower inflorescence scent without any influence on carotenoid derivatives.     

Variability in the Essential‐Oil Composition of Sideritis scardica Griseb. from Native Bulgarian Populations

The essential‐oil composition of six native populations of Sideritis scardica from Bulgaria was studied by GC‐FID and GC/MS analyses. Altogether, 37 components, representing 73.1 to 79.2% of the total oil content were identified. Among them, α‐pinene (4.4–25.1%), β‐pinene (2.8–18.0%), oct‐1‐en‐3‐ol (2.3–8.0%), phenylacetaldehyde (0.5–9.5%), β‐bisabolene (1.3–11.0%), benzyl benzoate (1.1–14.3%), and m‐camphorene ( 1 ; 0.3–12.4%) were the main compounds. All samples were characterized by low contents of oxygenated mono‐ and sesquiterpenes (≤1.6 and 2.3%, resp.). Principal component analysis (PCA) and cluster analysis (CA) showed a significant variability in the chemical composition of the studied samples as well as a correlation between the oil profiles and the ecological conditions of the natural habitats of S. scardica.     

Volatile Compounds of Viola odorata Absolutes: Identification of Odorant Active Markers to Distinguish Plants Originating from France and Egypt

Absolutes isolated from Viola odorata leaves, valuable materials for the flavor and fragrance industry, were studied. Violets are mainly cultivated in France and Egypt and extracted locally. The absolutes of the two origins showed different olfactory profiles both in top and heart notes, as evidenced by sensory analysis. The aims of this study were i) to characterize the volatile compounds, ii) to determine the odorant‐active ones, and iii) to identify some markers of the plant origin. Two complementary analytical methods were used for these purposes, i.e., headspace solid‐phase microextraction (HS‐SPME) using different fiber coatings followed by GC/MS analysis and gas chromatography – olfactometry/mass spectrometry (GC‐O/MS) applied to violet leaf extracts. From a total of 70 identified compounds, 61 have never been reported so far for this species, 17 compounds were characterized by both techniques (with seven among them known from the literature), 23 compounds were solely identified by HS‐SPME GC/MS (among them only two being already mentioned as components of violet absolutes in the literature), and, finally, 30 compounds were only identified by GC‐O/MS. According to the HS‐SPME GC/MS analyses, ethyl hexanoate and (2E,6Z)‐nona‐2,6‐dienol were specific volatile compounds of the sample with French origin, while (E,E)‐hepta‐2,4‐dienal, hexanoic acid, limonene, tridecane, and eugenol were specific of the samples with Egyptian origin. Additional compounds that were not detected by HS‐SPME GC/MS analysis were revealed by GC‐O analyses, some of them being markers of origin. Pent‐1‐en‐3‐ol, 3‐methylbut‐2‐enal, 2‐methoxy‐3‐(1‐methylethyl)pyrazine, 4‐ethylbenzaldehyde, β‐phenethyl formate, and 2‐methoxy‐3‐(2‐methylpropyl)pyrazine revealed to be odorant markers of the French sample, whereas cis‐rose oxide, trans‐rose oxide, and 3,5,5‐trimethylcyclohex‐2‐enone were odorant markers of the Egyptian samples.     

Variability of n‐Alkanes and Nonacosan‐10‐ol in Natural Populations of Picea omorika

This is the first report of population variability of the contents of n‐alkanes and nonacosan‐10‐ol in the needle epicuticular waxes of Serbian spruce (Picea omorika). The hexane extracts of needle samples originated from three natural populations in Serbia (Vranjak, Zmajeva?ki potok, and Mile?evka Canyon) were investigated by GC and GC/MS analyses. The amount of nonacosan‐10‐ol varied individually from 50.05 to 74.42% (65.74% in average), but the differences between the three investigated populations were not statistically confirmed. The results exhibited variability of the composition of n‐alkanes in the epicuticular waxes with their size ranging from C₁₈ to C₃₅. The most abundant n‐alkanes were C₂₉, C₃₁, and C₂₇ (35.22, 13.77, and 12.28% in average, resp.). The carbon preference index of all the n‐alkanes (CPI_total) of the P. omorika populations (average of populations I–III) ranged from 3.3 to 11.5 (mean of 5.9), while the average chain length (ACL) ranged from 26.6 to 29.2. The principal component and cluster analyses of the contents of nine n‐alkanes showed the greatest difference for the population growing in the Mile?evka Canyon. The obtained results were compared with previous literature data given for other Picea species, and this comparison was briefly discussed.     

Comprehensive Study of Mediterranean (Croatian) Propolis Peculiarity: Headspace,Volatiles, Anti‐Varroa‐Treatment Residue,Phenolics, and Antioxidant Properties

Eight propolis samples from Croatia were analyzed in detail, to study the headspace, volatiles, anti‐Varroa‐treatment residue, phenolics, and antioxidant properties. The samples exhibited high qualitative/quantitative variability of the chemical profiles, total phenolic content (1,589.3–14,398.3 mg GAE (gallic acid equivalent)/l EtOH extract), and antioxidant activity (11.1–133.5 mmol Fe²⁺/l extract and 6.2–65.3 mmol TEAC (Trolox^® equivalent antioxidant capacity)/l extract). The main phenolics quantified by HPLC‐DAD at 280 and 360 nm were vanillin, p‐coumaric acid, ferulic acid, chrysin, galangin, and caffeic acid phenethyl ester. The major compounds identified by headspace solid‐phase microextraction (HS‐SPME), simultaneous distillation extraction (SDE), and subsequent GC‐FID and GC/MS analyses were α‐eudesmol (up to 19.9%), β‐eudesmol (up to 12.6%), γ‐eudesmol (up to 10.5%), benzyl benzoate (up to 28.5%), and 4‐vinyl‐2‐methoxyphenol (up to 18.1%). Vanillin was determined as minor constituent by SDE/GC‐FID/MS and HPLC‐DAD. The identified acaricide residue thymol was ca. three times more abundant by HS‐SPME/GC‐FID/MS than by SDE/GC‐FID/MS and was not detected by HPLC‐DAD.     

Chemosystematic Analyses of Gingidia Volatiles

The leave volatiles of six Gingidia species from New Zealand and Australia and the seed volatiles of G. grisea were characterized by solid‐phase microextraction (SPME)‐GC/MS analysis. This technique, using a small quantity of samples and automated extraction, gave repeatable results, with maximum sensitivity for medium volatility compounds. The major monoterpenes among the volatiles, i.e., β‐phellandrene ( 4 ), limonene ( 6 ), and γ‐terpinene ( 5 ), and phenylpropanoids, i.e., estragole ( 3 ), (E)‐anethole ( 7 ), and myristicin ( 1 ), showed to be useful chemotaxonomic markers. For G. grisea leaves and seeds, similar compositions were detected, characterized by high contents of 4 . As leaves were more readily available for study than seeds, they were used for further investigations. The G. grisea leaf volatiles showed infraspecific variation in the ratio of 4 / 5 between and within sites of collection. The G. montana leaf volatiles also showed infraspecific variation, with high contents of 3 at one site and high contents of 7 at another. The SPME‐GC/MS analysis of G. montana herbarium voucher specimens resulted in the identification of further chemotypes for this species. The volatiles of the G. amphistoma samples were all dominated by 7 and those of the G. haematitica samples were rich in 5 . Moreover, single plants of two Australian Gingidia species were analyzed; the volatiles of G. harveyana showed high concentrations of 5 and 7 , whereas those of G. rupicola were dominated by 5 and 1 .