Definition: The word "acarina" is a scientific term in the field of botany used to describe the type of plant cell that contains an internal sac or space where pollen grains are stored during pollination, often known as the pollen storage sac (also called the stigmol sac). This space also contains other types of structures related to the pollen grain (the nucleus, mitochondria, chloroplasts) and is used by the plant cells during the life cycle. The exact function and size of a "carina" in each type of flower and plant are not well understood but it seems like the term was commonly used for some time. For example: The pollen storage sac (also called the stigmol sac) is often referred to as the 'pistil sac' or the 'pollen storage sac'. In other words, it's a small space in the pollen grain that contains the pollen.

Acarina