Plant Systematics and Evolution

, Volume 299, Issue 2, pp 389–401

Stylar polymorphism, reciprocity and incompatibility systems in Nymphoides montana (Menyanthaceae) endemic to southeastern Australia

Original Article

DOI: 10.1007/s00606-012-0729-y

Cite this article as:
Haddadchi, A. Plant Syst Evol (2013) 299: 389. doi:10.1007/s00606-012-0729-y


Heterostyly is a stylar polymorphism that has been shaped by the evolution of floral characters adapted for efficient pollen transfer. Different types of stylar polymorphism are described in which the discrete characterization of the exact polymorphic type (e.g., distyly vs. stigma-height dimorphism) requires detailed floral measurements (e.g., sex-organ reciprocity). In clonal and aquatic Nymphoides montana, although the presence of two floral morphs that contain styles of two lengths has been previously reported, no studies have quantitatively estimated the level of reciprocity and/or described the stylar condition. Morphological variations and incompatibility relationships were explored between the two morphs in three southeastern Australian populations. In this study, one population is characterized as stigma-height dimorphism (i.e., two morphs with discrete variation in stigma height but little variation in anther height), whereas the other two populations are typical distylous (i.e., two morphs for reciprocal stigma and anther height). Nymphoides montana is dimorphic in a wide range of ancillary characters, including corolla size, stigma size, shape and papillae morphology, and pollen size, number and exine sculpture. Following glasshouse pollinations, full incompatibility systems were observed in the distylous populations, whereas the stigma-height dimorphic population showed between-morph variation in the extent of incompatibility. Despite the variation in sex-organ reciprocity and incompatibility, other lines of evidence appear to assure the maintenance of the stylar polymorphism in the N. montana study populations. All populations are nearly isoplethic (i.e., both morphs in equal frequencies), which is indicative of balanced polymorphisms that appear to be maintained by legitimate pollen transfer between the morphs.


Ancillary characterDistylyIndex of reciprocityIsoplethyReproductive outputStigma-height dimorphism

Copyright information

© Springer-Verlag Wien 2012

Authors and Affiliations

  1. 1.Department of BotanyUniversity of New EnglandArmidaleAustralia
  2. 2.Ecosystem ManagementUniversity of New EnglandArmidaleAustralia