Floral sex expression along branches of the monoecious species Apodanthera undulata follows a typical cucurbit pattern: staminate buds are common at early nodes and become less frequent as branches elongate, while pistillate buds are more common at the more distal nodes of a branch. However, this developmental sequence is not sufficiently canalized to explain the male-phase plants in this
... [Show full abstract] species. Male-phase plants have shorter internodes than monoecious-phase plants and also produce and mature fewer flower buds. These data indicate that male plants probably experience less favorable growing conditions than monoecious plants. Finally, the distributions of staminate and pistillate buds along branches and the length of their associated internodes indicate that floral bud production is affected by the same factors that determine branch growth. Consequently, seasonal changes in growth conditions are hypothesized to affect both flower bud production and sex expression.