when plants release reproductive cells in the air to reproduce asexually, what is it called?

Plants reproduce asexually through a process called "vegetative reproduction" or "clonal propagation." This can include various methods such as fragmentation, budding, and producing specialized reproductive structures (e.g., bulbs, tubers, runners, rhizomes). However, releasing reproductive cells in the air for asexual reproduction, as described in your question, is not a common trait in plants. Plants typically release reproductive cells like pollen or spores for sexual reproduction.