A study of the Floral Biology of Viciaria amazonica (Poepp.) Sowerby (Nymphaeaceae) Ghillean T. Prance (1) Jorge R. Arias (2) Abstract Victoria and the beetles which visit the flowers in large numbers, and to collect data A field study of the floral biology of Victoria on V. amazonica to compare with the data of amazonica (Poepp.) Sowerby (Nymphaeaceae) was Valia & Girino (1972) on V. cruziana. made for comparison with the many studies made in cultivated plants, of Victoria in the past. In thE: study areas in the vicinity of Manaus, four species HISTORY OF WORK ON THE FLORAL of Dynastid beetles were found in flowers of V. BIOLOGY OF VICTORIA. amazonica, three of the genus Cyclocephala and one o! Ligyrus . The commonest species of beetle The nomenclatura( and taxonomic history proved to be a new species of Cyclocephala and was found in over 90 percent of the flowers studied. of the genus has already been summarized in The flowers of V. amazonica attract beetles by Prance (1974). where it has been shown that their odour and their white colour on the first the correct name for the Amazonian species day that they open. The beetles are trapped in the of Victoria is V. amazonica, and not the more flower for twenty-four hours and feed on the starchy carpellary appendages. Observations were frequently used name, V. regia. The taxonomic made of flower temperature, which is elevated up history is not treated further here. to 11 aC above ambient temperature, when the flower Victoria amazonica has been a subject of emits the odour to attract the beetles. Observa­ tions on beetle frequency, the number of floral interest in Amazonia for many years, and parts, seed dispersai and the evolutionary develop­ there are severa( extant versions of the lndian ment of cantharophily are also presented. legend attached to the plant. One of these versions is given below. lt shows that the Tupi lndians regarded the flowers of Victoria as !NTRODUCTION objects of great beauty. The Tupi Legend of Victoria We, a botanist and an entomologist wor­ king together in Amazonia, decided to inves­ The elders of the tribe say that Nauê, the beautiful daughter of the chieftain, fell in love with tigate the floral biology of Victoria amazonica. the moon when she saw its reflection in the water Since the subject proved very interesting the one night. From then on Nauê went to look at the study became more detailed than we had ori­ reflection, which, the shaman said, was the prince ginally intended it to be. Although there is of the region of Iuaca . After several days the moon much literature about the floral biology of disappeared from the Iake, and Nauê became very sad and fell sick for a month. One night in her Victoria, most of the significant work has been love-sick delirium Nauê saw the moon reflected carried out in greenhouses in Europe, and not again in the Iake, and to embrace the body of her in the plant's native habitat. Accordingly, we lover she threw herself in the water and disappea­ have tried to study the plant in central Ama­ red. 'l'upã the god touched by the fate of Nauê transformed her into the most beautiful flower of zonia over a one-year period, in order to con­ the lakes, Victoria amazonica. firm observations made in greenhouses, to integrate the various other studies made in Many years after the lndian legend carne the field of some aspects of the subject, to into existence, Victoria amazonica was disco­ find out more about the inter-relation between vered by scientists of the western world, and ( 1 ) - Instituto Nacional de Pesquisas da Amazônia e B. A. Krukoff Cu rato r of Amazonian Botany, The New York Botanical Garden. ( 2) - Instituto Nacional de Pesquisas da Amazônia, Manaus. ACTA AMAZONICA 5(2): 109-139. 1975 - 109 from the fírst they made observatíons and recorded was 1O. 2°C at 19: 15 hours (3). Knoch comments on aspects of the floral biology. observed the flowers opening in the early Schomburgk, (1837), was the first botanist to evening, and emmitting a strong odour at that note the presence of beetles in the flowers time, the flowers closing the following mor­ of V. amazonica. Schomburgk mentioned the ning, changing colour during the day and re­ genus Trichius as the possible identification opening on the second day between 17:00 and of the beetles, and this observation was re­ 18:00 hours, when the pollen was released. peated by Lindley (1838) in his description of He could not observe the pollinators in Ger­ the synonym Victoria regia based on Schom­ many, but assumed that they were trapped in burgk's material . the flower during the second day, and released Bridges, (in Hooker 1847), described the when the flowers opened to release the evening opening of the flowers and noted the pollen. He also noted that self-pollination was change of colou r in the petals. He also des­ possible, and that the fertilized flowers soon cribed the fruity smell of the flowers of Victo­ became submerged. Knoch also studied the ria which he had observed in Bolívia. physiology and chemistry of the carpellary Fitch and Hooker, (1851), made observa­ appendages, including the chemical changes tions on the first opening of the first green­ which took place during flowering and the house material to flower in England. co2 released by the respiration. Malme, (1907). in a detailed taxonomic Planchon, (1850-1851). was the first person discussion of V. cruziana treats the floral bio­ to comment on the temperatura difference logy little, but he refers to previous work, between the air and the interior of the flower. such as that of Knoch and Caspary, and cites H e recorded a 6°C. difference in the material Cyc/ocephala as a visitar to the flowers. grown in Ghent, Belgium . Otto (1952). also Archangeli, (1908). made a similar study ínvestigated the flower temperatura in mate­ of V. amazonica grown at Pisa, ltaly. He rial grown at Hamburg, and recorded a 5° tem­ concentrated on the fertílization aspects, and peratura difference. obtained reasonable seed-set from self-fertili­ Caspary (1855a,b) also made detailed zation. H e found that the stigma remained studies of the temperatura changes (see Fig. receptiva on the second night. Archangeli re­ 1) and commented that cross-pollination was fered to the literatura citing the scarab beetle necessary for seed-set; an observation which Cyc/ocepha/a castanea Oliv. as the pollinator, was later disproved by various workers, in­ and he commented that it was probable that cluding the present ones. more than one species of beetle was involved The most detailed European work on the in the pollination; a fact that we have now floral biology of V. amazonica is that of Knoch established. (1899), who studied the anatomy, the flower Decker, (1939), said that flowers studied opening, and the temperatura changes of in Amazonian Brazil showed a temperatura cultivated material . Knoch studied the tem­ difference of 11° - 14°C, between the envi­ peratura changes of individual parts of the ronment and the flower interior. He also said flower in considerable detail, and showed that that self-fertilization did not occur in V. ama­ most of the heat is generated from the car­ zonica. pellary appendages, but that the paracarpels Many other authors of the present cen­ also produce heat. (The terms used here for tury have commented on these observations, these parts follow those of Caspary, (1878). or have repeated in part the work of some of and of Knoch, as there has been much confu­ the previous workers, for example: Arbor sion in the nomenclatura of the floral parts). (1920). Knoll (1956). Werth (1956), Meeuse Knoch compa.red his results with those of (1961), Percival (1965), Sculthorpe (1967). Caspary . The maximum temperatura differen­ Kugler (1970), Gottsberger (1974). Weidlich ce between ambient and flower which he (pers. comm.). ( 3 l - Some of hls results are reproduced here for cornparison with ou r results. (Fig. 2). 110- Prance & AriM .. , .... , f ', / ' ' I \ / \ ' / " ' / ' / , -- -'"- I ' I ' I ', I ' I I ' \ I ' ' I ' I ' \ ' f ., , ' ' I \ / ... ..... __ ., --· ' ', I ',', f \ I ' I \ \ ........ __ _,. \ 4 ·· ... -···· ·.. B .············ .. ~ . Qj a. .... E ···· ·· .... Qj ~16~--~~--~~--"1 6 18 20 ~--22 ~24~-- ~--2 --r.-4 --~r---~----~8 10 --~=---~~--12 14 r.r16 --~~--11 8 ~20--- Ti me Fig. 1. Graph of Caspary's results (1855) of the temperature of V. amazonica flowers. A flower temperature B: air temperature. Gessnerl (19601 1962). studied the flower tions in V. amazonica, and they noted the opening and showed clearly that it was rela­ colour and smell changes in the flowers . They ted to light intensity. The flowers opened as studied the emission of odour using the neu­ darkness increased . H e showedl by masking tra! red technique described by Vogel (1962). f lowers, that they could close in darkness at and showed that the odour carne from the any time after 16:00 hours . He also cited the petals as well as from the interior of the presence of the scarab beetle Cyclocephala flower. They made temperature readings and castanea Oliv. recorded a maximum of 7. 5°C difference Valia and Girino (1972) made a detailed between the ai r and the flower interior. Un­ two-month study of the floral biology of Victo­ fortunately, their temperature readings w ere ria cruziana, in its native habitat, in the Pro­ made in cut flowers taken to the laboratory, vince of Corrientes, Argentina. Their interes­ so that we do not have an exact comparison ting work enabled us to compare some as­ with our results which were obtained in the pects of our work on V.