To view pollen grains individually requires magnification of 1,000 power or more. Pollen grains are so small that they easily can pass through the tightest window screens. The grains of windborne pollen are light and dry and are negatively charged. Mother Nature designed female plants to receive these grains of pollen. Each female tree has thousands of pistillate flowers, each one designed by nature as a highly efficient collector for the airborne male pollen of that particular species.
Female flowers stand up in the wind.
With their large positively charged surface areas of moist stigmas, they attract, hold, absorb, and ultimately use the male pollen. Female plants are nature's air-scrubbers, trapping ambient pollen grains and leaving the surrounding air free of this allergenic form of biopollution. In the spring of the year in almost any modern city, we are all breathing in several hundred grains of pollen with each breath of air we take. In some areas people are breathing in thousands of pollen grains with every breath. In the sterile male-predominant modern urban landscape, humans have replaced the female plants, and we are now the most effective natural pollen traps.