Orange Pinwheel Marasmius

Marasmius siccus

orange_pinwheel_marasmius.jpg

Photo of orange pinwheel marasmius, tiny, orange, pleated, gilled mushroom
The orange pinwheel marasmius is a tiny mushroom with an orange, bell-shaped, pleated cap, white gills, and a skinny brownish stalk.
Lisa K. Suits
Not recommended/not edible
Family

Marasmiaceae

Description

Tiny; orange, bell-shaped, pleated cap; white gills; skinny brownish stalk. Grows scattered to many on dead leaves, wood, and twigs. July–October. Cap bell-shaped, becoming convex and knobbed or sunken in center; rusty orange to orange; with deep, wide, radial pleats. Gills broad; spacing distant; white to very pale yellow; gills attached or free. Stalk skinny; white to pale yellow at top, shading to brownish black at base; texture dry, tough, smooth; wiry and strong. Spore print white. Spores magnified are spindle- to club-shaped, smooth, large.

Lookalikes: There are many other little Marasmius species, which differ mainly in color.

Size

Cap width: ¼–1¼ inches; stalk length: 1–2½ inches; stalk width: 1⁄64–1⁄32 inch (wirelike).

Habitat and conservation

Grows scattered to many on dead leaves, wood, and twigs of deciduous trees. After a good rain, the various little marasmius species are often the first mushrooms to appear.

image of Orange Pinwheel Marasmius distribution map
Distribution in Missouri

Statewide.

Status

Not edible.

Life cycle

This little mushroom will shrivel up in dry conditions and completely revive when it rains. The Latin word "siccus" means "dry." Mushrooms exist most of the time underground or within rotting logs as a network of cells (mycelium) connected to tree roots, rotting material, and/or the soil. When ready to reproduce, the mycelium sends up the mushroom, a reproductive structure. Spores are produced in the gills and are released to begin new mycelia elsewhere.

Human connections

Mushrooms decorate nature the way wildflowers do, adding to our pleasure on hikes. Like wildflowers, even the smallest of fungi can turn out to be strikingly beautiful, when you take a closer look. Discovering these wonders can bring out our childlike sense of awe.

Ecosystem connections

This is one of the many fungus species that live on decaying forest litter. It and other such saprobic fungi play an important role in breaking down the staggering amount of leaves produced each year and returning their nutrients to the soil—an unglamorous but vital role in the ecosystem.