ABSTRACT
Dactylis glomerata L., cocksfoot, or orchardgrass as it is commonly known, is widely used as a forage grass in the temperate world. As a genus Dactylis is subject to differing taxonomic interpretations in different regions of its natural range (Europe, Asia, North Africa and the Canary Islands). There are no modern taxonomic treatments which interpret all forms on the same basis. Here we follow Stebbins’s interpretation that Dactylis glomerata L. is monotypic, consisting of one diverse species complex (Stebbins and Zohary 1959; Stebbins 1971). The genus however, is clearly on the cusp of speciation with many overlapping diploid, tetraploid and a hexaploid subspecies and some reduction in fertility when different diploid forms are crossed (Parker and Borrill 1968; Borrill 1977).
