Scarlet bonnet

Appearance

The cap initially has a sharply conic shape, but expands to a narrow bell-shape or a broad cone in maturity, typically reaching 0.5 to 1.2 cm in diameter. The cap margin, which is initially pressed against the stem, is opaque or nearly so at first. It is scarlet red when fresh and moist, becoming orange or yellowish orange before losing moisture. The mushroom is hygrophanous, and fades to an orange buff color when dry. The flesh is thin, the same color as the cap, fragile, and without any distinctive taste or odor. The gills are ascending-adnate or attached by a tooth, subdistant to close, with 14–16 gills reaching the stem. Additionally, there are two or three tiers of lamellulae—short gills that do not extend fully from the cap edge to the stem. The gills are narrow, and yellowish or with a reddish tinge at first; the margins are paler and the same color as the faces. The stem is 2–4 cm long and 1–2 mm thick, and roughly equal in width throughout. It is tubular, fragile, initially pruinose , polished and smooth with age, pale yellow, becoming whitish, with the base often dirty yellow or brownish. ''Mycena adonis'' mushrooms are inedible.The spores are narrowly ellipsoid, nonamyloid, and measure 6–7 by 3–3.5 µm. The basidia are four-spored and measure 20–22 by 6–7 µm. The cheilocystidia and pleurocystidia are abundant and similar in shape and markings, 40–58 by 10–15 µm, tapering somewhat on either end and usually with a long needle-shaped neck . The cystidia are generally smooth, but when dried material is mounted in potassium hydroxide for observation under light microscopy, an amorphous substance apparently holds spores and debris around the neck or apex, making them appear encrusted. The flesh of the gill is very faintly vinaceous-brown when stained in iodine. The cap flesh has a thin, poorly differentiated pellicle with a region of slightly enlarged cells beneath it; the remainder is filamentous, and the filamentous portion stains vinaceous-brown in iodine.

Naming

There are several other mycenas with which ''Mycena adonis'' could be confused. ''M. acicula'' is typically a smaller mushroom with a deep orange-red cap rather than the typical bright salmon-pink color of ''M. adonis''. Since the colors and sizes of ''M. acicula'' and ''M. adonis'' are similar, a microscope is needed to reliably distinguish between them, with spore size and shape being different. ''M. strobilinoides'' can be distinguished from ''M. adonis'' by its orange cap and amyloid spores. ''M. aurantiidisca'' can be distinguished from ''M. adonis'' by it lack of scarlet to pinkish tones in the cap and lack of gelatinized cortical hyphae. ''Mycena oregonensis'' is differentiated from ''M. adonis'' by its orange to yellow cap and lack of scarlet to pinkish tones. ''M. roseipallens'' has a smaller fruit body, wider spores, a less intensely colored and less conical cap, and grows on the decaying wood of elm, ash, and alder.

Distribution

The fungus is found in western North America, and in 2007, it was reported from the valley of the Ussuri River in the northeast of China. It is also found in Europe and the Canary Islands. ''Mycena'' specialist Alexander H. Smith has found the species in Washington, Oregon, and California.

Habitat

The fruit bodies of ''Mycena adonis'' grow solitarily or in groups in conifer forests, and appear in the spring and autumn. The fruit bodies grow in groups or scattered on needle beds under spruce and hemlock in the wet coastal conifer forests, or in the higher mountains, where it is not uncommon in the spring and autumn months. In one instance, fruit bodies were found growing on the deciduous trees Spanish Maple and willow near Amsterdam, Holland. It was hypothesized that the bark of these trees had become more acid in recent years because of increasing atmospheric pollution , providing a more suitable substrate for the fungus.