After open pollination aP. atrisanguineaplant with 2n= 84 (12 x) produced offspring with 2n= 56 and 2n= 74. Controlled crosses betweenP. atrisanguineaandP. ambigens(2n= 82) yielded hybrids with 2n= 70 and 2n= 72. All these plants were vigorous. Meiotic observations onP. ambigensandP. atrisanguineashowed that both had an irregular meiosis with variable numbers of bivalents, univalents and multivalents.