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

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 fruiting abundance. Additionally, the number of insect visitors on the flowers was monitored. The investigations of specimens originating from 4 populations in central-eastern Poland (Wyzyna Lubelska Upland) were conducted in the Botanical Garden of Maria Curie-Sklodowska University. It was found that morphological features of the analysed flowers, i.e. the 6-angular ovary and the perianth tube, which is 2-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 April and May at air temperature of 12-13 degrees C. The plants produced, on average, 3 flowers per stem, 84.2 flowers per 1 m(2), and 6.2 capsules per 1 m2. The flowers released nectar with a moderate amount of sugar and produced high quantities of pollen. Mononychus punctumalbum Herbst. and bumblebees were found to be the main flower pollinators.