Irish Lousewort

Irish Lousewort, Pedicularis sylvatica ssp. hibernica

The Louseworts (Pedicularis spp.) make up a large (some 400 representatives) genus of hemiparasitic plants that have been shown to take up secondary metabolites, such as alkaloids from their hosts (1). Their rather unfortunate common name came from the belief in the past that they caused lice and liverworms in cattle (2). Ireland is home to two species, Common Lousewort (Pedicularis sylvatica) found on damp heaths and moors and the taller Marsh Lousewort (P. palustris) which is found on bogs, heaths and wet grasslands (3). P. sylvatica can be further divided into two subspecies based on a number of features, the most obvious being the presence or absence of hairs on the calyx and pedicles. Those lacking hairs are placed in P. sylvatica ssp. sylvatica, while those with are called Irish Lousewort, P. sylvatica ssp. hibernica. A further, hairy subspecies, P. sylvatica ssp. lusitanica, is found in Portugal but the hairs on this taller plant are found only on the angles and not all over (4). The Irish Lousewort was first described by David Webb in 1956 from a samples collected in Co. Kerry, and he noted that the plant was distributed almost entirely around the west coast of Ireland (4). While this is still the case, it has been since reported Scotland(5), Norway (6) and Wales to name a few. The sample pictured was seen on the Beara Peninsula in west Co. Cork.

Irish Lousewort, Pedicularis sylvatica ssp. hibernica

References:

1. Schneider and Stermitz, 1990. Biochemistry 29 pp. 1811-1814
2. Phillips, 1977. Wild Flowers of Britain p. 56
3. Sterry, 2004. Collins Complete Guide to Irish Wildlife p. 242
4. Webb, 1956. Watsonia 3 pp. 239-241
5. Birks and Madsen, 1979. Journal of Ecology 67 pp. 825-842
6. Skogen, 1966. Blyttia 24 pp. 361-367
7. Rich, 1994. Watsonia 20 pp. 61-71