A. palustris was first described from Himberg (Germany) by Jaquin in 1786 and its name literally means "from marshes", a reference to its preference for marshy habitat.

This is a close relative of A. laxiflora and at first sight is often mistaken for that species, particularly as its  found in similar damp to wet conditions, closer inspection however reveals differences and most notably in the shape and pattern of the lip. Whereas A. laxiflora has a plain or lightly spotted white central lip with lateral lobes that are strongly reflexed, A. palustris shows strong purple striation and lateral lobes that are only marginally curved backwards, being better described as flared. It is a tall plant that is normally around 60cms but has been recorded as high as 100cms.

As with A. laxiflora, this species can be abundant in its preferred sites but unfortunately, wetland draining is severely reducing its numbers. Although it can occur in various damp situations it shows a preference for saline substrates and is at its most common in seaside fens, meadows and dune slacks. A. palustris has a widespread distribution throughout most of continental Europe including Scandinavia but as with A. laxiflora is absent from the UK mainland.

This species is not especially varied although a particularly large form, mediterranea has been recorded from the Aegean, Italy and Spain. In the warmer parts of its range it flowers from April and can be declining by the beginning of May. In more temperate zones it may still be in full flower through to July.

The pictures here are from the Province of Lecce in southern Italy and date from the 9th of May.