Onygena equina

Onygena equina
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Eurotiomycetes
Order:	Onygenales
Family:	Onygenaceae
Genus:	Onygena
Species:	O. equina
Binomial name
Onygena equina ( Pers. (1800)
Synonyms[2]
Lycoperdon equinum Willd. (1787)[1]

Onygena equina, commonly known as the horn stalkball, is a species of

Taxonomy

The species was first

British botanist Harry Marshall Ward was able to cultivate the fungus and described its life cycle in an 1899 publication. He determined that the white powder on the fruit bodies were chlamydospores, which were formed at the ends up erect hyphae. As the fruit bodies mature, the hyphae that held the chlamydospores fuse and form the peridium of the fruit body. This is followed by additional changes in the internal hyphae, which form claw-like filaments that push their way into the internal spaces and cavities of the fruit bodies. These claw-shaped hyphae form asci, which disappear as the spores mature, leaving the spores lying loose in the gleba.^[6]

William Broadhurst Brierley studied spore germination in the 1910s. He determined that fully grown ("ripe") ascospores can be germinated after a lengthy resting period, but a pretreatment with gastric acids reduced the time required. The time that mature spores need to germinate is correlated to the thickness and color of the spore wall. Treating "unripe" ascospores and chlamydospores with gastric juice did not decrease their germination time, and decreased their viability the longer they were treated. These observations confirmed and extended those already published by Ward; taken together, the results indicate that the spores need to pass through the digestive tract of a cow to be viable.^[7]

Habitat and distribution

The fruit bodies of Onygena equina grow singly or in tufts or clusters, on rotting horns of cattle and sheep, as well as remains of hooves. Fruiting occurs from spring to autumn.^[4] Fruit bodies are often overlooked by mushroom hunters, as animal remains are not a typical substrate for macrofungi. The species has been recorded from Europe and North America.^[5]

References