Pollination rigida", this allows the plant to self-pollinate, which is useful when biotic pollinators in the environment have decreased. It is possible for a plant have varying pollination methods, including both biotic and abiotic pollination. The orchid "Oeceoclades maculata" uses both rain and butterflies, depending on its environmental conditions. More commonly, pollination involves pollinators (also called pollen vectors): organisms that carry or move the pollen grains from the anther of one flower to the receptive part of the carpel or pistil (stigma) of another. Between 100,000 and 200,000 species of animal act as pollinators of the world's 250,000 species of flowering
Pollen tube This is a gene level regulation in which gene loci of the gynoecium allow either self pollen to slowly grow, stop growing or burst while faster growth of outcrossed pollen occurs, increasing genetic diversity. The main component is that this step determines which pollen grains are compatible to grow and parts of the style, and female embryo contribute in determining. Using hybrid species and crossing pollen, the interaction with the style and pollen was found to influence growth of the pollen tube based on compatibility. Pollen tube growth begins from when the pollen attaches to the stigma. It is followed