The organization in pollengrains of some early conifers

Abstract

The in situ pollen grains of Lebachia piniformis (Schloth. pars) Florin, Lebachia hypnoides (Brongn.) Florin, Ernestiodendron filiciforme (Schloth.) Florin, Walchianthus crassus Florin and W. cylindraceous Florin show a monosaccus which girdles the central body leaving its proximal and distal faces free from the saccus. A two-lipped, linear suture along the longer equatorial axis is mostly borne by the broader, bladder-free and evidently the proximal face. The distal face bears a broad sulcus usually lined by two folds lying across the longer equatorial axis in polar view of the flattened specimens. Saccus is distally inclined. This organization is shown to be different from that in the pollen grains of Cordaitales.