Pollen tube through wind, water or pollinators. The last step before fertilization is the growth of the pollen tube to transfer non-motile sperm to the protected egg. Pollen tubes are unique to plants and their structure had evolved over plant history. The pollen tube formation is complex and the mechanism is not fully understood, but is of great interest to scientists. Pollen is produced by the stamen, the male reproductive organ of the flower. Each pollen grain contains a vegetative cell, and a generative cell that divides to form two sperm cells. The pollen is delivered by the opening of anthers for
Pollen count Pollen count Pollen count is the measurement of the number of grains of pollen in a cubic meter of air. High pollen counts can sometimes lead to increased rates of an allergic reaction for those with allergic disorders. Usually, the counts are announced for specific plants such as grass, ash, or olive. These are tailored to common plants in the measured areas. Mild winters with warmer days lead to an increase in pollen counts while colder winters lead to delayed pollen release. In the UK, the public announcement of the pollen count was popularised by Dr. William Frankland, an immunologist.