John and Gerry's    Orchids of Britain and Europe

Platanthera holmboei

P. holmboei was first described by Lindberg from Cyprus in 1942 and takes its name from the noted 20th century Norwegian botanist J. Holmboe. The genus Platanthera comprises approximately one hundred species, the majority of which are found in Asia and the Americas. Of the only eight species of this genus represented in Europe, P. holmboei is one of it's rarer orchids, occurring extremely locally through the eastern Mediterranean as far south as Israel and Syria.

This species produces highly scented flowers, that are at their most productive at night, thus ensuring they are pollinated almost exclusively by night flying moths. Nectar is stored in the very long spur and consequently can only be accessed by an insect with a long proboscis, again restricting the variety of potential pollinators that will be attracted to the plant. Unlike its close relatives, it prefers a site in light to mid shade, usually at altitude and often in pinewoods. The single plant illustrated here was found growing within thick bramble scrub that allowed minimal light penetration.  

This is a distinctive species, that can easily be confused with its close relative P. chlorantha , the Greater Butterfly Orchid. They are indeed very similar and some botanists consider them synonymous, whilst others view P. holmboei as a variety or subspecies at best. The key distinguishing characteristics of P. holmboei are it's smaller overall size and it's smaller, greener flowers.

The pictures are from an upland site near Ramljane in Southern Croatia where this species is extremely rare. The pictures date from the middle of May.