Figure 2. Enantiomeric configuration of linalool emitted by flowers of Penstemon digitalis. Upper panel: comparison of linalool emitted from coriander (upper GC trace) vs. cut P. digitalis flowers (lower trace) on a chiral GC column. Coriander shows a racemic mix dominated by (S)-(+)-linalool (right peak), whereas P. digitalis emits only that enantiomer (arrow). GC trace for (R)-(-)-linalool not shown (see text). Lower panel: EI-quadrupole mass spectra for (S)-(+)-linalool from coriander (above) and for linalool emitted by flowers of P. digitalis (below).