Pollen Morphology and Ultrastructure of Laurelia,Laureliopsis and Dryadodaphne (Atherospermataceae [Monimiaceae])

Pollen morphology and ultrastructure of Laurelia novae-zelandiae A. Cunn., L. sempervirens (Ruiz et Pavón) Tulasne, Laureliopsis-philippiana (Looser) Schodde and Dryadodaphne trachyphloia Schodde are described. Laurelia, Laureliopsis and Dryadodaphne have medium-sized, isopolar, globose to globose-ellipsoidal pollen which is either dicolpate (Dryadodaphne, rarely in Laureliopsis) or meridionosulcate, with a median encircling aperture with two wider parts centered at the poles (Laurelia, most pollen of Laureliopsis). Exine is tectate-columellate with an uneven foot layer showing irregular discontinuities. A few tangentially-aligned lamellae show some resemblance to an endexine and in some sections there appears to be an intergradation between these lamellae and small tangentially flattened foot layer parts. The intine consists of an outer channelled zone, with radial (Laurelia sempervirens) or tangential (Dryadodaphne) alignment of channels and an inner intine of homogeneous appearance. The outer intine is thicker in apertural regions and the inner intine is thicker within the apertures of Laureliopsis and Dryadodaphne. The pollen grains of 6 of the 7 genera of Atherospermataceae are compared in tabular form. Although pollen grains show links with other Monimiaceae (sensu lato), it is sufficiently distinct to support the existence of the Atherospermataceae as a separate family. It is acknowledged that, on other grounds, a good case can be made for retention of the group as a subfamily within the Monimiaceae.