Floral development of dioecious species and trends of floral evolution in Piper sensu lato

摘要: The initiation of the floral parts (mainly stamens and carpels) is described for four dioecious species Piper: Piper polysyphorum C. DC., P. bavinum pedicellatum pubicatulum DC. order resembles that in perfect flowers some species, such as amalago. carpels are initiated simultaneously, most cases: three primordia. In polysyphorum, carpel tips split into two lobes, so finally a four- or five-lobed stigma will be formed when ovary fully developed. staminodes (exactly, staminodial primordia) female same male remain until ovaries enclosed. unisexual have reduced to two. reduction stamen staminode (staminodial primordium) number accompanied by change their positions from opposite alternate. After staminodes, or, exactly primordia, flowers, central part apex forms ring meristem which triangular. primordia (often three) on points meristem. evolutionary trends sensu lato discussed. (C) 1998 Linnean Society London.