After the summer of the second year of growth the plant produces seeds. One individual can produce 100,000 to 180,000 seeds. These seeds are released in close proximity to the plant and can remain viable for over 100 years. The invasive common mullein prefers dry and sandy soils, but is adaptable to many soil types.
primary porosity. (geology). Natural porosity in petroleum reservoir sands or rocks. 1  Facebook. 2  Twitter.rimary porosity. (geology). Natural porosity in petroleum reservoir sands or rocks. 1  Facebook. 2  Twitter.
Porosity is further classified as total porosity and effective porosity. Total porosity is defined as the ratio of the entire pore space in a rock to its bulk volume. Effective porosity is the total porosity less the fraction of the pore space occupied by shale or clay.