Dactylorhiza kerryensis - Irish Marsh-orchid

Phylum: Magnoliophyta - Class: Liliopsida - Order: Orchidales - Family: Orchidaceae

Another orchid that is difficult to identify. It is recorded in Ireland and is sometimes referred to as Dactylorhiza occidentalis.

Description

This is another robust-looking marsh-orchid (around 25cm tall), and there is much argument about its range due to confusion with other orchids including the Early Marsh-orchid. The flowers have broader and flatter lips (sometimes slightly recurved) with three shallow lobes, unlike Early Marsh-orchids which have distinctly recurved lips. The flowers of D. kerryensis are rose pink but sometimes darker purple or, rarely, white. There are up to 4 leaves which are often spotted on the upper surface.

Distribution

This orchid is endemic to Ireland, where the extent of its distribution is much disputed.

The Western Marsh-orchid Dactylorhiza majalis is recorded in Europe from Northern Spain, as far north as southern Scandinavia, and into central Europe including Slovenia

Habitat

The Irish Marsh-orchid favours neutral or slightly alkaline soils and is found on the edges of loughs, in dune slacks and in damp hollows in short-sward grassland. They cope well with open sunny positions.

Flowering times

The Irish Marsh Orchid flowers in May and June.

Hybrids and Varieties
Varieties:
Dactylorhiza occidentalis var. kerryensis always has unspotted leaves and is reported to be a shorter plant with smaller, paler flowers; it may be closely allied to the Southern Marsh-orchid Dactylorhiza praetermissa.
Hybrids:
Dactylorhiza x dinglensis is a hybrid with Heath Spotted-orchid Dactylorhiza maculata.
Dactylorhiza x aschersoniana is a hybrid with Early Marsh-orchid Dactylorhiza incarnata.
Dactylorhiza x braunii is a hybrid with Common Spotted-orchid Dactylorhiza fuchsii and is reported from County Clare.

Etymology

The genus name Dactylorhiza means 'finger-like roots', while the specific epithet kerryensis means 'from Kerry' and the synonymous name occidentalis means 'from the west'.

Reference sources

Pictures:

Pictures by kind permission of Simon Tarrant

Books:

The Plant List

Sue Parker (2009) Wild Orchids in The Burren; First Nature

Henrik Pedersen Field Guide to the Orchids of Europe and the Mediterranean (2019); Kew

Anne and Simon Harrap (2005) Orchids of Britain and Ireland; A&C Black

Pierre Delforge (2005) Orchids of Europe, North Africa and the Middle East; A&C Black