Obdiplostemony in the genus Allium L.

Early floral organogenesis has been investigated in a number of Allium spec ies from various subgenera and sections (A. I ramosum, A. angulosum, A. gal anthum, A. sphaerocephalon, A. oreophilum, A. cernuum, A. moly). Comparativ e studies and earlier results show a considerable uniform pattern of the se quence of floral organ inception in the genus as a whole. Fusion of extende d filament bases and shifting outwards of the originally inner stamina has been observed in Allium oreophilum after stamina differentiation only. A di sturbance of alternation in the androeceum has been detected in Allium kuju kense, A. umbilicatum, and A. ferganicum as well. Those configurations and that of Trillium apetalon can be described by the term "obdiplostemony", ap plied in a broad sense also to flowers with a perianth, not differentiated into calyx and corolla. According to this definition, mature flowers with t wo stamen whorls are obdiplostemoneous in the case of an interrupted altern ation between androeceum and perianth, with stamina of the outer stamen who rl opposite the parts of the inner whorl of the floral envelope and/or stam ina of the inner stamen whorl opposite the parts of the outer whorl of the floral envelope. In the genus Allium obdiplostemony occurs in several subge nera and sections of different flower traits. In the case of Allium oreophi lum and A. kujukense however, a special type of obdiplostemony suggests a c lose relationship.