reticuloid

Formal generic pollen descriptions are provided for each of these genera. Study of the pollen of these two genera reveals that they possess a number of similar palynological features, including sulcate apertures, reticuloid to reticulate exine sculpturing that sometimes consists of banded or beaded muri, a columellate interstitium with columellae frequently hanging from the tectum or only weakly attached to the nexine, and tectate-perforate to semitectate pollen grains. Pollen of Compsoneura, however, can be distinguished from that of Virola by (1) its nexine which is generally twice as thick as that in Virola, (2) its consistently more or less solid, nonlamellate nexine, and (3) its consistently inconspicuous intra-exinous, sexinous cavities. Within Compsoneura, pollen of section Coniostele is decidedly more advanced than that of section Compsoneura. Virola exhibits a wide range of exine sculpturing patterns, allowing recognition of three basic pollen types. Species of Pollen Type I have basically tectate-perforate grains although sometimes their pollen may be more or less reticuloid, and the exine surface or muri are usually psilate.