Analysis of inflorescence organogenesis in Eastern gamagrass, Tripsacum dactyloides (Poaceae): The wild type and the gynomonoecious
sex form (GSF) mutant of eastern gamagrass was found in 1981 and differs from the wild type by conversion of previously male flowers to seed setting structures (Dewald and Dayton, 1985).
Bidens contains hermaphroditic and gynodioecious species (Sun and Ganders 1986); Tetramolopium is characterized by monoecious and gynomonoecious
species (Lowrey 1986); whereas Dendro-seris (Crawford et al.
Following Lloyd (1980), we also use the term sexually dimorphic to collectively refer to taxa with dioecious, subdioecious, polygamodioecious, or gynodioecious systems; monomorphic refers to taxa with hermaphroditic, monoecious, andromonoecious, gynomonoecious
, or polygamomonoecious systems (see Table 1 for definitions).
From these so-called gynomonoecious
plants with the sex-reversal trait, Dewald is screening for agronomic traits such as disease resistance, to develop new germplasm lines.
It was produced from a controlled pollination of a gynomonoecious
sex form (GSF) diploid (2n = 2x = 36) with a monoecious tetraploid (2n = 4x = 72).
The remaining sexual systems are found exclusively among the dicots: Gynomonoecious
species include 7% of the flora and are in Abrotanella, Cuminia, Chenopodium, Erigeron, and Lactoris; the one gynodioecious species is in Rhaphithamnus; polygamous taxa are scarce and included in Empetrum and Parietaria, as are andromonoecious taxa included in Cyperaceae and Asteraceae.
Following Lloyd (1980), we also use the term sexually dimorphic to refer collectively to taxa with dioecious, subdioecious, polygamodioecious, or gynodioecious systems; monomorphic refers to taxa with hermaphroditic, monoecious, andromonoecious, gynomonoecious
, or polygamomonoecious systems.