Biology of flowering and insect visitors of Iris aphylla L. (Iridaceae)

Abstract

The paper presents the morphology of the flower of Iris aphylla L., which is a protected species in many European countries.The study comprises phenological observations of flowering and assessment of nectar and pollen production, and flowering and fruitingabundance. Additionally, the number of insect visitors on the flowers was monitored. The investigations of specimens originating from 4populations in central-eastern Poland (Wyżyna Lubelska Upland) were conducted in the Botanical Garden of Maria Curie-SkłodowskaUniversity. It was found that morphological features of the analysed flowers, i.e. the 6-angular ovary and the perianth tube, which is2-fold longer than the ovary, are typical for the taxon I. aphylla [=I. aphylla var. typica L.]. The first flowers developed at the turn of Apriland May at air temperature of 12–13 °C. The plants produced, on average, 3 flowers per stem, 84.2 flowers per 1 m2, and 6.2 capsules per1 m2. The flowers released nectar with a moderate amount of sugar and produced high quantities of pollen. Mononychus punctumalbumHerbst. and bumblebees were found to be the main flower pollinators.