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
Grains of Selim Grains of Selim Grains of Selim are the seeds of a shrubby tree, "Xylopia aethiopica", found in Africa. The seeds have a musky flavor and are used as a spice in a manner similar to black pepper, and as a flavouring agent that that defines , the dominant style of coffee in Senegal. It is also known as Kani pepper, Senegal pepper, Ethiopian pepper, and (historically) Moor pepper and Negro pepper. It also has many names in native languages of Africa, the most common of which is in the Wolof language (this is the name used on most packages of