First Description of Cypripedium calceolus and Cypripedium calceolus var. citrina B. HERGT in Romania: Morphology, Pollination and Conservation Status

Cypripedium genus is represented by 59 species and nothospecies (species of hybrid origin), mainly distributed across North, Central and South America, Europe and Asia, but absent from Madagascar and Australia. The most important characteristic of this genus is their showy and large labellum, which transformed into the specific slipper-shaped, vividly coloured, inflated pouch. In Romania, the genus is represented by one species only, Cypripedium calceolus. The article contains the first description of a newly discovered population in Prahova County, as well as a complete illustration of a Cypripedium calceolus flower pollinated by a female bee of the Lasioglossum genus. The flowers are passive traps pollinated by bees of particular type and size. The article describes in detail different mimicry (deceit) pollination strategies employed by the orchid in order to exploit its insect pollinators (generalized food deception mimicry, shelter mimicry, nest/brood-site mimicry, rendezvous attraction). Using advanced techniques of ultra-macro photography, details of floral organs are illustrated in order to describe in great detail the intriguing deceptive pollination mechanisms and mimicry strategies employed by the Slipper Orchids to attract their highly specific and rather scarce pollinating insects. Along with the detailed description and illustration of the common single-flowered plants, we also describe rare Cypripedium calceolus f. biflorum plants in Prahova County and present for the first time in Romania, a unique Cypripedium calceolus var. citrina individual, found in 2019, in Suceava County.