perforated or having window-like openings.
having openings or translucent areas ('windows').
With small slits or window like openings or areas so thinned as to be translucent.
(adj.) ( Iversen and Troels-Smith, 1950) Describing a class of pollen grains characterized by large, window-like spaces lacking a tectum. Comment: The term is accepted as a category in the classification system of Iversen and Troels-Smith (1950) and was especially established to include lophate pollen grains of the Compositae. Although useful for defining a class of pollen grains the term is not recommended in descriptions. Many such grains can be described as lophate.
pierced with small window-like openings.