Sarcosphaera coronaria

Back in May, several photographs of fungi from Vancouver Island were posted for identification and appreciation to the UBC Botanical Garden Forums by forum member mikephillips. Mike gave permission to use this one that he posted for appreciation. Thanks for sharing, Mike!

Sarcosphaera coronaria (synonyms: Sarcosphaera crassa, Sarcosphaera exima) is commonly known as crown fungus or the violet-crowned cup. According to Mushrooms Demystified by David Arora, this solitary fungus is common under pines and other conifers in the Sierra Nevada, the Cascades, and the Rocky Mountains. The hollow, round, lobed ball of the fruiting body often pops up in the spring, though summer and autumn emergences also occur. The walls of the fruiting body split and fold back at maturity to form several pointed segments forming a crown-like cup. The initially smooth, but later scaly, interior is revealed when this occurs. What particularly stands out is that the interior of the cup is greyish at first, but darkens with age to pink or lilac, and yet later to a deeper purple-brown. Older individuals may be confused with Scleroderma polyrhizum, but the two species can be differentiated by the presence of a powdery spore mass in the cup of Scleroderma polyrhizum or the pink/purple colour interior of Sarcosphaera coronaria.

Crown fungus is an ascomycete or sac fungus. Its nonmotile spores are formed within structures called asci (ascospores). When stained with IKI or Melzer’s reagent, the amyloid tips of the asci will turn blue because of the starch content. The dispersed spores develop into underground ectomycorrhizae. These contain yellowish or clear & glossy hyaline hyphae in a gelatinous matrix, and are associated with coniferous symbionts. In the underground stage, this fungus species is apt to be mistaken for a truffle at first glance, but can be distinguished easily as they have a hollow interior. Because of their similarity to truffles, this fungus (and others from the genus) were once even given its own truffle genus, Caulocarpa. However, they are now placed within the Pezizaceae because of the asci with amyloid tips.

In Mushrooms Demystified, it is noted that Sarcosphaera coronaria is not recommended for consumption. While rated highly by some to eat, the fungal bodies are difficult to clean and a few people are adversely affected by it. The texture has been described to be like a rubber eraser that has been softened with time. If that sounds appetizing to you, and you would like to try it, it’s recommended to cook it thoroughly beforehand. Wikipedia also notes that it is an arsenic accumulator.

Sarcosphaera coronaria

One response to “Sarcosphaera coronaria”

  1. Bonnie

    Golly, at first glance I thought that was a dinosaur egg that had cracked open.

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