Functional andromonoecy in Prosopis alba (Mimosaceae)

HOC, P. S., AMELA GARCÍA, M. T. & PALACIOS, R. A.

Beitrage zur Biologie der Pflanzen

Schraudolf, H., Vogel, S. & Weberling, F. Duncker & Humblot

Lugar: Berlin; Año: 1995 vol. 69 p. 191 - 218

Observations on floral morphology and floral visitors were made. Stigmatic receptivity, pollen viability and reserves, and nectar composition were tested. An experiment of self-compatibility was performed. We found that: a) there are 3 floral morphs with different pistil lengths, b) flowers with medium and short length styles are not receptive, thus the species is andromonoecious, c) style precocity does not involve protoginy, d) the stigma is never contacted by the visitors in short and medium styled morphs, e) rain affects stigma receptivity and pollen viability, consequently, fruit production, f) long styled flowers have most pollen rich in proteins, medium and short styled flowers have most pollen rich in oil, g) rain modifies nectar composition and flower utilization, h) no fruits were obtained by spontaneous self-pollination, i) the hymenopterans Xylocopa splendidula, X. ordinaria, Megachile spp., Trigona mombuca and Colletes sp. are efficient pollinators, j) Apis mellifera produces geitonogamy, k) the bees Dialictus sp., Plebeia sp. are pollen robbers, l) the wasps Polybia ignobilis, P. ruficeps, Brachigastra lecheguana and the ants Camponotus sp. may benefit P. alba eating phytophagous larvae, m) other taxa of Hymenoptera, Coleoptera and Diptera are nectar and/or pollen robbers.