Fig. 1

Gas chromatographic representation of differences between chemotypes of Oenothera harringtonii. A. Total ion chromatogram of floral scent from two accessions, the upper trace (black) from a linalool+ plant and the lower trace (gray) from a plant lacking this compound. Other than the internal standard (toluene; T), numbered peaks indicate floral scent compounds (Monoterpenes: (1) β-myrcene, (2) (Z)-β-ocimene, (3) (E)-β-ocimene, (4) Ocimene epoxide, (5) R-(−)-linalool; Diterpenes: (10) Isophytol; Sesquiterpenes: (6) β-caryophyllene, (7) α-humulene, (8) Caryophyllene oxide, (9) Methyl farnesoate, (11) E,E-farnesol), with retention times given for a typical polar (EC-wax) GC column. B. Separation of linalool enantiomers on a chiral GC column, confirming that flowers of O. harringtonii exclusively emit (R)-(−)-linalool. Trace a = racemic (1:1) (R)-(−) and (S)-(+)-linalool, trace b = synthetic (R)-(−)-linalool, trace c = (S)-(+)-linalool in floral headspace of Clarkia breweri, trace d = floral headspace of O. harringtonii from Florence, Colorado (FLO), and trace e is the same sample spiked with (R)-(−)-linalool. In both panels, vertical axis shows counts (abundance) and horizontal axis shows retention time (minutes)