SEARCHING FOR A FOVEOLATE POLLEN EXINE

Ninety-five scanning electron micrographs of pollen exines with perfor ations, lumina, pits, or depressions were photocopied from the palynol ogical literature, examined by computerized image analysis, and catego rized using existing numerical definitions for reticulate, microreticu late, scrobiculate, punctate and foveolate. For comparison, we also re corded descriptive terms used for these pollen surfaces in the origina l literature source. Most exines examined were reticulate, microreticu late or scrobiculate. Only two were punctate, an anomaly we attributed to sampling bias. No exines were foveolate. We concluded that pollen exines with foveolate surfaces are very rare or non-existent. We also demonstrated that many overlapping sculpture terms are used to describ e very similar exines, a situation that may adversely affect the usefu lness of palynological information in larger systematic data sets.