C. longifolia. was first described by Fritsch from Sweden in 1753 and its name refers to the lanceolate leaves which are also the source of its common name, the Sword Leaved Helleborine.

This is one of the most familiar of Spring orchids and can be found throughout most of Europe and into Asia as far as the Himalayas but notably absent in Scandinavia and rare in Britain. Although it prefers a position in the partial shade of cool, open woodlands, it seems to show little reluctance in colonizing open grassland and road verges in full sun. It can often be abundant and despite favouring alkaline substrates, its acceptance of decalcified soils often results in it being the dominant species and in many cases the only orchid over large areas.

C. longifolia cannot be easily confused with any other orchid except perhaps in a limited area in the Aegean where it comes into contact with a close relative C. conferta. Although this potential confusion mostly arises further East and outside the geographical parameters of this site, it does occur on the islands of Lesbos and Samos. C. longifolia is reported to be very rare in the Aegean but nevertheless present and the authors find it difficult to separate the two species. C. conferta further east is a morphologically different species with a distinctive compact, crowded inflorescence. On Samos however, the species exhibits a much looser flower spike difficult to distinguish from C. longifolia.
 
C. longifolia comes into flower in early April in warmer climes but can be as late as June in more temperate regions. The photos are from southern England and southern France dating from the first week in May in both regions.