Several ecophysiological observations in Genlisea

Thanks to successful cultivation of Genlisea species, it is possible to comp lement field research with important details . This can be helpful particularly in acquiring better knowledge oflife functions . Six species (G. fi liformis, G. hispidula, G. pygmaea, G. repens, G. roraimensis and G. violacea) are cultivated in the Bot. Gardens Libe rec (CR). According to occasional field observations ,Genlis ea species often grow in water. Never theless , one must question ifthey are true aquatic plants or if they are in some sense semiterrestrial. We can look for stomata which are considered special aerial organs. Stomata are mostly absent in submerged pla nts but there are several except ions having rudimentary stomata. Lloyd (1942) writes: "All the species are small plants which inhabit swampy places and apparently live mostly submersed in shallow water; only the inflorescence, as in Utricularia , projecting above the surface. This is to be inferred from the abs ence of stomata ". In contradiction to this opinion, Elsa Fromm-Trinta (1979) published phot ogr aphs ofdistinct stomata in G. filiformis, G.pygmaea, G. repens and G. violac ea. She writes: "Stomata are only in the dorsal epidermis of G. repens and G. pygmaea. " I have also stud ied G. repens and G. pygmae and G. hispidula and G. rora imensis . I have also found stomata, but I have been surprised by observing the stomata only in the lower (abaxial) surface ofleaves. According to Czech authorities (e. g. Dostli11954 , et c. ), the "dorsal" near the upper surface of a leaf. Th e term "dorsal" is evidently used in different meaning in botany! It is better to say that stomata occur in the abaxial surface of leaves . That is however an arrangement which is normal in many purely terrestrial plants . I have found both open and closed stomata in various specimens ofGenlisea . I believe,therefore that stomata are working and are not rudimentary. Genlisea species are semiterrestrial plants, green leaves ofwhich are aerial organs.They can survive also below water for long periods, but I have never observed morphological ada ptations to that cond ition . Many semite rrestr ial Utricularias tU. graminifolia, U. prehensilis etc . ) make shor t ae rial terrestrial leaves and very long ribbon-shaped aqua ti c leaves. These plants, re lated to Genlisea , are probably more adapted to aquatic life in comparison with Genlisea . Th e inv estigation of traps in cultivated specimens is of interest, I have compared twomost different species, namely G. hispidula and G.pygmaea . You find only one type of trap in G. hispidula, but in G. pygmaea there are two evidently different type s of traps . The traps ofthe first type are very long, with very small ves icles, narrow necks and with long arms. They are in a vertical position. The traps of the second type are shor t, but the vesicles are three times larger and the necks are three times wider than in the firs t type . Th e arms are also very short, with fewer windings . Th ese trap s are more or less horizontal. Analysis of contents in the traps has bee n surprising. The traps of G. hisp id ula have been quite empty, but the traps ofG. pygmaea , cul tivated in the same soil and in the same condit ions, have been full of prey. In the vesicles I have see n remains oftwo species ofNemathelmintes, Arthropoda, and also single-cell a lgae (Baccillari ophyzae and Desmidi ales). In ne cks, I have fr equently observed livin g Nematodes . Comparing