Pilobolus crystallinus
Encyclopedia
Pilobolus crystallinus var. crystallinus, commonly known as the "Dung Cannon" or "Hat Thrower", is a species of fungus belonging to the Mucorales
order. It is unique in that it adheres its spores to vegetation, so as to be eaten by grazing animals. It then passes through the animals' digestive systems and grows in their feces. Although these fungi only grow to be 2 – tall, they can shoot their sporangium
, containing their spores, up to 2 m (6.6 ft) away. Due to an increase of pressure in the vesicle
, the sporangium
can accelerate 0–45 mph in the first millimeter of its flight, which corresponds to an acceleration of an incredible 20000 g. Using a mucus-like substance found in the vesicle
of the fungus, the sporangium
can adhere itself onto whatever it lands, thus completing its life cycle.
The basionym
of this species is Hydrogera crystallina F.H. Wigg. 1780.
The ability of this fungus to cause problems for florists was noted in the scientific literature in 1881:
inhibits radial growth at the hypha
e.
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 elonates 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.
Mucorales
The Mucorales is the largest and best studied order of Zygomycete fungi. Members of this order are sometimes called pin molds.-Systematics:...
order. It is unique in that it adheres its spores to vegetation, so as to be eaten by grazing animals. It then passes through the animals' digestive systems and grows in their feces. Although these fungi only grow to be 2 – tall, they can shoot their sporangium
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
, containing their spores, up to 2 m (6.6 ft) away. Due to an increase of pressure in the vesicle
Subsporangial vesicle
A subsporangial vesicle is a vesicle which is below the sporangium on a fungus.Is often used in the turgor-building and release to launch the sporangium from the stalk of the fungus using this spore-dispersal method.e.g...
, the sporangium
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
can accelerate 0–45 mph in the first millimeter of its flight, which corresponds to an acceleration of an incredible 20000 g. Using a mucus-like substance found in the vesicle
Subsporangial vesicle
A subsporangial vesicle is a vesicle which is below the sporangium on a fungus.Is often used in the turgor-building and release to launch the sporangium from the stalk of the fungus using this spore-dispersal method.e.g...
of the fungus, the sporangium
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
can adhere itself onto whatever it lands, thus completing its life cycle.
The basionym
Basionym
Basionym is a term used in botany, regulated by the International Code of Botanical Nomenclature...
of this species is Hydrogera crystallina F.H. Wigg. 1780.
The ability of this fungus to cause problems for florists was noted in the scientific literature in 1881:
... this small fungus had proved this season to be an expensive annoyance to florists engaged in winter forcing flowers. Rose-growers especially had found it to interfere seriously with their profits. The injury was caused by the projection of the sporangia which covered the flowers and leaves of the roses as if profusely dusted with black pepper. The flowers were almost unsaleable as the first impression was that the black dots were aphids.
Description
This fungus normally grows beneath the surface - a sensitivity to oxygenOxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
inhibits radial growth at the hypha
Hypha
A hypha is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.-Structure:A hypha consists of one or...
e.
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 elonates at the apex, but does not rotate. In stage II, the sporangiophore develops a sporangium
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
. 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
Transmission electron microscopy
Transmission electron microscopy is a microscopy technique whereby a beam of electrons is transmitted through an ultra thin specimen, interacting with the specimen as it passes through...
has shown that the surface of the sporangium
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
is covered with crystals of two distinct sizes. The larger crystals enclose spines having a central pore.