gymnadenia_odoratissima_l.

Gymnadenia odoratissima (L.) Rich. - Orchidaceae
short spurred fragrant orchid , scented gymnadenia, Wohlriechende Händelwurz, Duft-Händelwurz

Perennial herb, up to 30cm high, native to Central Europe; leaves lanceolate; flowers white to purple, fragrant.
„The fragrant orchid is characterized by intense vanilla-like scented flowers.“
http://de.wikipedia.org/wiki/Wohlriechende_H%C3%A4ndelwurz

The flower fragrance may be characterised as 'aromatic spicy-floral' with a basic accord consisting of phenylethanol, benzyl alcohol, and benzaldehyde, „…and deriving its pleasant character from a series of minor but olfactorily important components such as citral, cinnamic aldehyde, cinnamic alcohol, eugenol and vanilline. In chemical terms, the scent of Gymnadenia odoratissima is quite closely related to that of Nigritella nigra.“
[The scent of orchids: olfactory and chemical investigations., Kaiser, R., Basel 1993, 177]

benzaldehyde
(cherry-like)

phenylacetaldehyde
(green-floral, honey)

benzyl acetate
(sweet floral)

eugenol
(clove-like)

vanillin

Of 44 volatiles identified in the flower scent, seven were physiologically active in pollinators: Benzaldehyde (8.0% day, 5.7% night), phenylacetaldehyde, benzyl acetate (20.8% day, 17.2% night), 1-phenyl-2,3-butandione (7.6% day, 8.4% night), phenylethyl acetate (24.7% day, 20.8% night), eugenol (4.6% day, 3.1% night), and one unknown compound. Phenylacetaldehyde increased during the night: 9.4% day, 24.7% night - the most pronounced change in odour emission. On GC, vanillin co-eluted with (Z)-isoeugenol (1.9% day, 3.3% night; sum).
[Floral scent emission and pollinator attraction in two species of Gymnadenia (Orchidaceae)., Huber, F.K., Kaiser, R., Sauter, W., Schiestl, F.P., Oecologia, Vol.142(4), 2005, 564-575]
http://behav.zoology.unibe.ch/sysuif/uploads/files/Byers_2.pdf

Dietrich, A.G., Flora regni borussici, vol.1 t.66 (1832-1833)
http://plantillustrations.org/species.php?id_species=485171