MORPHOLOGICAL STUDIES OF THE NYMPHAEACEAE. XII. THE FLORAL BIOLOGY OF CABOMBA CAROLINIANA
1982; Wiley; Volume: 69; Issue: 9 Linguagem: Inglês
10.1002/j.1537-2197.1982.tb13389.x
ISSN1537-2197
AutoresEdward L. Schneider, John M. Jeter,
Tópico(s)Plant Parasitism and Resistance
ResumoObservations have been made on the pollination ecology of Cabomba caroliniana Gray in Texas. Flowers are trimerous with morphologically similar perianth parts. The adaxial corolla spurs are nectariferous and attract small Diptera (e.g. Notiphila cressoni and Hydrellia bilobifera ). Anthesis occurs for 2 consecutive days with flowers opening about 10:00 a.m. and closing around 4 p.m. on each day. First‐day flowers have short, indehiscent stamens and longer pollen‐receptive stigmata which arch outward over the nectaries. In 2nd‐day flowers the stamens have elongated to the level of the stigmata and extrorse dehiscense occurs above the nectaries. Stigmata of 2nd‐day flowers are pressed together at the center of the flower and are nonreceptive to pollen. Insects attracted to 2nd‐day flowers in search of nectar become dusted with pollen (due to the position and extrorse dehiscence of the anthers) and as insects fly to 1st‐day flowers, achieve cross‐pollination by virtue of the stigmata position over the nectaries. Seed anatomy is similar to that of other nymphaeaceous genera (i.e., abundant perisperm, little cellular endosperm, a haustorial nucellar “tube,” and a small dicotyledonous embryo). Pollination morphology and comparative xylem anatomy support the segregation of Cabomba from the Nymphaeaceae, sensu stricto. The anatomical correlations between seeds and the myophilous pollination syndrome (found elsewhere in Nymphaeaceae, sensu lato), however, suggest a phyletic relationship.
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