Evidence of gynodioecy in Portulacaria pygmaea: Fruit production on predominantly staminate plants

• First documentation of fruit development on predominantly staminate plants of Portulacaria pygmaea . • Pollen from fruiting "male" plants successfully fertilizes female plants; controlled pollination confirms fertility. • Gynodioecy documented in young seedlings under both greenhouse and outdoor cultivation. • Findings parallel gynodioecious systems in P. afra and P. kaokoensis , indicating sexual lability in Portulacaria . • Rapid fruit maturation (24–48 h) and occurrence among >20 cultivated plants suggest low-frequency phenomenon. Portulacaria pygmaea Pillans is a succulent endemic to South Africa and Namibia, consistently described as strictly dioecious. Here I report three independent observations of fruit development on predominantly staminate ("male") plants cultivated in Japan during summer 2025. These observations occurred among a collection of >20 cultivated P. pygmaea plants. "Male" identity was confirmed through production of staminate flowers with functional pollen. Controlled pollination experiments demonstrated that pollen from fruiting "male" plants successfully fertilized confirmed female plants, confirming retention of male function. Seeds formed on "male" plants contained visible embryos; naturally dispersed seeds germinated, demonstrating reproductive viability. Despite daily monitoring, pistillate flowers on "male" plants were not directly observed, suggesting extremely brief or inconspicuous anthesis. These observations indicate gynodioecy—populations consisting of female individuals and predominantly staminate individuals that occasionally produce pistillate flowers. This finding parallels gynodioecious systems documented in P. afra and P. kaokoensis , suggesting evolutionary lability in sex expression within Portulacarioideae. The phenomenon may have been overlooked in previous studies due to the low frequency and minute size of pistillate flowers on "male" plants.