Hat-thrower fungus

A species of Pilobolus

This fungus normally grows beneath the surface – a sensitivity to oxygen inhibits radial growth at the hyphae. According to McVickar (1942), and later amended by Ootaki et al. (1993), the development of P. crystallinus may be divided into six stages: In stage I, the sporangiophore initially elongates at the apex, but does not rotate. In stage II, the sporangiophore develops a sporangium. In stage III, after the development of the sporangium, there is a temporary cessation of growth. In stage IV, a subsporangial vesicle expands beneath the sporangium. This is followed by stage V, where the spore matures, and the region of hypha directly below the subsporangial vesicle continues elongating. Finally, in stage VI, the subsporangial vesicle bursts and throws the sporangium into the air. Scanning and transmission electron microscopy has shown that the surface of the sporangium is covered with crystals of two distinct sizes. The larger crystals enclose spines having a central pore.