Marasmius siccus, or orange pinwheel, is a small orange mushroom in the Marasmius genus, with a "beach umbrella"-shaped cap. The tough shiny bare stem is pale at the top but reddish brown below, and the gills are whitish. The stem is 3–7 centimetres (1.2–2.8 in) tall and the cap is 0.5–2.5 centimetres (0.20–0.98 in) wide.
At a microscopic level, the club-shaped spores are very long and thin, being roughly 19 µm by 4 µm. The distinctive cheilocystidia are broadly club-shaped with finger-like protrusions at the far end. Such cells also sometimes occur in other related mushrooms and they are known as "broom cells of the siccus type".
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- "Marasmius siccus". University of Arkansas. Retrieved 16 February 2015.
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