Aperture (botany) pollen grain. Aperture (botany) Apertures are areas on the walls of a pollen grain, where the wall is thinner and/or softer. For germination it is necessary that the pollen tube can reach out from the inside of the pollen grain and transport the sperm to the egg deep down in the pistil. The apertures are the places where the pollen tube is able to break through the (elsewhere very tough) pollen wall. The number and configuration of apertures are often very exactly characteristic of different groups of plants. The biggest class of plant species, the Eudicots, usually have three apertures
Xylan (coating) Xylan (coating) Xylan is a fluoropolymer-based industrial coating. Generally, it is applied in a thin film to the target material. Xylan is generally used to reduce friction, improve wear resistance, and for non-stick applications. Additionally, it can be used to protect a metal from corrosion. The most commonly known application is in non-stick cookware but Xylan coatings have also been used extensively in the automotive industry and for corrosion protection in the oil and gas industry. Xylan is the umbrella trademark for most of the Whitford Corporation fluoropolymer coatings line. Xylan is made of low friction, wear resistant composites of