Pollen as large as about 90–100 µm. In angiosperms, during flower development the anther is composed of a mass of cells that appear undifferentiated, except for a partially differentiated dermis. As the flower develops, four groups of sporogenous cells form within the anther. The fertile sporogenous cells are surrounded by layers of sterile cells that grow into the wall of the pollen sac. Some of the cells grow into nutritive cells that supply nutrition for the microspores that form by meiotic division from the sporogenous cells. In a process called microsporogenesis, four haploid microspores are produced from each diploid sporogenous cell
Shroud of Turin in Edessa, Turkey. Mark Antonacci argues that the pollen evidence and flower images are inherently interwoven and strengthen each other. However it was subsequently determined that Baruch's work was "scientifically unsafe", and Danin thereafter disowned the publication of this work. Danin stated in 2011, that: "In 2001 we brought most of the slides to Prof. Dr. Thomas Litt who is an expert palynologist and has very sophisticated microscopic equipment. Prof. Litt concluded that none of the pollen grains he saw could be named at a species level. Hence, all the conclusions drawn from previous palynological investigations of Dr. Frei's material