MORPHOLOGY AND DISTRIBUTION OF SPECIES IN THE MEDICAGO-MUREX COMPLEX

Morphological, cytological, and agronomic characteristics are reported for 560 accessions of the Medicago murex Willd. complex collected from countries bordering the Mediterranean and grown in field plots in Western Australia. All plants of the 2n = 16 taxon were shown to have white flecks on the leaves, a mean number of florets on each peduncle of < 2.5, and usually no ridges on the edge of the pod coils. Plants of the 2n = 14 taxon never had white leaf flecks, 99% of accessions had a mean number of florets > 2.5, and most had three distinct ridges on the pod coils. Plants of the two taxa were equally vigorous and both were widespread, occurring sympatrically in many Mediterranean countries. The 2n = 16 and 2n = 14 taxa do not cross and should be recognized as separate species. A reexamination showed that Willdenow's original material of M. murex was most likely to be of the 2n = 16 species. We suggest that the name of the 2n = 14 species is Medicago sphaerocarpos Bertol.