Pisumis often divided into three wild species, fulvum, (northern and southern) humile and elatius, in addition to the cultivated sativum. In this study, pea taxa representing both wild populations and cultivated accessions are scored for morphological characters, allozymes, RAPDs and ITS sequences. The relatively small number of morphological characters and allozymes precisely organize the species into traditional taxonomic groupings, perhaps in part reflecting the role morphology plays historically in pea classification. A much larger RAPD data set supports several of these same groupings. P. fulvum is clearly the most distinct of the pea taxa, while humile, elatius and sativum form a monophyletic group. RAPD trees, however, often show the southern humile populations forming a clade that is distinct from elatius, sativum and even northern humile. These results may support previous studies which suggest that northern humile may be the sister taxon to sativum. The current study presents only modest support for northern humile as the single closest relative of the domesticated pea. Additionally, a very small number of polymorphic ITS sites actually places northern humile further from sativum and reemphasizes the close affinity among all the non-fulvum peas. ISSR data are presently being collected to provide yet another measure of relationship among these taxa. Comparisons among all the data sets are also being made, and particularly the informativeness of increasing the number of RAPD markers.

Key words: ISSR, ITS, morphology, phylogenetics, Pisum, RAPDs