Relating to or affecting the outer wall or layer of a spore, especially in fungi and plants.
From Greek 'exo-' (outside) + 'sporos' (seed/spore) + '-al' (relating to). Botanical terminology that developed as microscopy revealed spore structure in the 19th century.
When fungi release millions of spores into the air, what actually floats around is just the exosporal layer—the tough outer coat that protects the living spore inside, kind of like the skin on an apple protects the fruit.
Complete word intelligence in one call. Free tier — 50 lookups/day.