Patterns Of Anomalous Floral Development In The Asian Passiflora (Subgenus Decaloba: Supersection Disemma)

Approximately 22 species of Passiflora are native to the Old World. All of these species are placed in subgenus Decaloba, supersection Disemma. Within Disemma, three species vary in stamen and carpel number (≤ eight stamens and five carpels). The mode of development was determined for two of the anomalous species, P. moluccana var. glaberrima and P. siamica. Ontogenetic patterns were compared to normal development in P. perakensis and P. holosericea. Passiflora siamica develops additional stamens through dédoublement of a single widened stamen primordium, while P. moluccana var. glaberrima exhibits congenital dédoublement where stamens emerge already doubled. Phylogenetic analysis using ITS and the trnL-F intron and spacer resolve the anomalous species as monophyletic and sister to P. perakensis. This signifies a single loss of genetic regulation in stamen and carpel number within Disemma. Floral whorls were examined across the Passifloraceae, Malesherbiaceae, Turneraceae, and Flacourtiaceae s.l.. Similar doubling in these families suggests that this Eurosid lineage may have a genetic propensity for variability in floral whorl number