Welsh Journals

Search over 450 titles and 1.2 million pages

NATURE IN WALES VOL. 8. No. I. SUMMER 1962. ERODIUM GLUTINOSUM IN WALES P. M. BENOIT The Common Storksbill, Erodium cicutarium (L.) L’Hér., is well known to be very variable and taxonomically difficult. Several segregates have been recognised-in Wales notably E. pimpinelli- folium Sibth., E. lebelii Jord., E. neglectum Baker f. & Salmon, and E. glutinosum Dumort. But most of them were poorly characterised and of doubtful taxonomic status, and they have been the source of much confusion. Andreas (1947), using modern cytological methods in Holland, found that there are two chromosome races in the group-a diploid and a tetraploid, which should be classed as full species and for which the correct names are, respectively, E. glutinosum Dumort. and E. cicutarium (L.) L'Her. sens. str. Recently, Larsen (1958) has reported a third chromosome race from Denmark, a hexaploid which he has named E. danicum but this does not concern us because it has not been found in the British Isles. The other segregates mentioned above are no longer maintained as species. E. pimpinellifolium and E. lebelii are included in the re- defined E. cicutarium. E. neglectum was also included in E. cicutarium by Clapham, Tutin and Warburg (1952) and Dandy (1958), but in fact clearly belongs to E. glutinosum it does not differ from E. glutinosum in any important detail. Yet, even with this simplified classification there is still con- siderable confusion about the group in Britain, because E. cicutarium and E. glutinosum as now understood are both variable and not very different from each other, their distinctness is often obscured by hybridisation, and none of the published descriptions are reliable, so that the wrong characters have been used to distinguish the two species. For example, only densely glandular plants have been thought to be E. glutinosum. But in the course of this study it has been found that both E. cicutarium and E. glutinosum vary with age and habitat from densely glandular to almost eglandular. E. glutinosum is actually more common with sparse glands. Reliance on glan- dulosity in identification has undoubtedly often led* to specimens of these plants being wrongly named.