Journal of Cell Science, Vol 9, 193-207, Copyright © 1971 by Company of Biologists

Submitted on November 19, 1970

Freeze-Etched Pollen Walls of Artemisia Pycnocephala and Lilium Humboldtii

¹ Department of Botany, University fo California Berkeley, California 94720, U.S.A.
² Deparment of Botany, University fo California Berkeley, California 94720, U.S.A.

Mature pollen was examined by freeze-etching. The fracture and etch faces of Artemisia ektexine are unstructured and homogeneous. The endexine fracture face contains particles in paired rows which correspond to the endexine lamellae with a central white line seen in osmium-stained thin sections. The intine fracture face in Artemisia is coarsely pitted and has very long fibrils. Small vesicles are observed on both sides of the plasmalemma. The fracture face of Lilium ektexine has radiating fibrils which end in a regular array near the surface; the etch face on the surface is smooth. In thin sections the staining of the Lilium ektexine differs from that of the core, giving evidence that the smooth ektexine surface is chemically distinct from the fibrillar core. The intine in Lilium shows no fibrils. Vesicles near the plasmalemma appear to be fusing with the plasmalemma creating smooth depressions in the particulate plasmalemma fracture face. The plasmalemma in both species is beset with particles in regular arrays.