Temperature-dependent floral longevity in two Helleborus species

• DOI: 10.1007/s00606-004-0261-9
• Publication Date: 2005-03-11T06:36:55Z
• Authors: J. L. Vesprini; E. Pacini
• Keywords: Anthesis; Receptivity; Ranunculaceae

The duration of pollen exposure and female receptivity in the winter flowering Helleborus bocconei Ten. and Helleborus foetidus L. were determined in the field. Experimental treatments were performed “in vitro” on cultivated flowers in order to investigate the abiotic factors regulating the patterns of pollen presentation and stigma receptivity. Correlation analysis with meteorological data in the field and the experimental results demonstrated temperature to be the main factor affecting the duration of anthesis and the number of anthers opening each day, whereas the duration of female receptivity mainly depends on whether or not pollination had occurred. This features may be an adaptation that allows biotic pollination under harsh environmental conditions.