Poster with record leave blades
(223 and 244 mm) of presented Utricularia cornigera clone
(formerly treated as
U. reniformis "Big Form").

       Utricularia cornigera is a quite recently recognized species of bladderwort that was described by Dr. Miloslav Studnička in 2009 (Studnička 2009). It is formerly known as a Utricularia reniformis "Big Form" or "Large Form" and also under cultivar description Utricularia 'Big Sister' (Rice and Studnička 2004).

       Although there is still some discussion among carnivorous plant experts about acceptance of segregation of Utricularia cornigera as a new species, it is admirable taxon anyway. The most obvious differing character is enormous size, compared to Utricularia reniformis sensu stricto. The dimensions can be enormous. For example the leaf blade was documented to be 17-18 cm wide, but it reached 22 - 24 cm in cultivation!!! Leaf petiole can be up to 46 cm long. Inflorescence frequently exceeds 1m height. The inflorescence documented on the images below was 125cm tall and held 11 flowers with dimensions of 58 - 65 mm. The pigmentation of U. cornigera flowers is slightly darker compared to U. reniformis. Signal stripes are orange, decorated with dark blue markings. But the most rigorous diagnostic character of U. cornigera compared to U. reniformis is completely different morphology of embryos or fresh germinated seedlings. Utricularia reniformis sedlings have 1 leaf primordium, lacking gas float, but the seedlings of U. cornigera are 6 - 8 leaved "octopus" with well-developed gas float, similar to that of Utricularia nelumbifolia (Studnička 2009).

       The cultivation of Utricularia cornigera is moderately complicated. It likes a lot of diffused light or half shaded - half sunny position. It can be kept for example among large pitchered Sarracenias. Preffered temperatures are between 15°C - 25°C. But tolerates also short time extremes of 30°C. The minimal temperature deadline seems to be 5°C, but safe temperature limit should be about 10°C. Utricularia cornigera grows well in semi-aquatic cultivation as well as soil cultivation in epiphytic mixture or well-softened mixture of coarse peat and large-grained perlite. The most important requirement is to provide really large cultivation container, at least 2 liters, but 5 liters would be optimal.

       The species Utricularia cornigera is circulating in the cultivation as several clones. I am personally proud to grow the most likely largest known clone of the species in cultivation, that was also taken as holotype of new species description.

References:

       Rice BM, Studnička M (2004): New cultivars Utricularia 'Big Sister', Utricularia 'Enfant Terrible'. Carnivorous Plant Newsletter 33(2): 52 - 55.

       Studnička M (2009): Brazilian bladderwort Utricularia reniformis is a blend of two species. Thaiszia - Journal of Botany 19: 131-143.

Inflorescence of Utricularia cornigera.