fungus

not listed

not listed

not listed

Scytinotus longinquus is a small, gilled mushroom. It occurs in North America, Chile, Argentina, eastern Australia, and New Zealand. It is found usually in groups or overlapping clusters, sometimes alone. In the Pacific Northwest it grows mostly on partially or completely debarked fallen logs and branches of red alder, rarely also on conifers, including western hemlock stumps. It obtains its nutrients from decayed wood (saprobic).

When it first appears, the cap is orb-shaped, pale ivory, orangish-white, tan, or pale orange, and the margins are rolled inward. As it ages it expands and the color changes. The mature cap is fan-shaped, kidney-shaped, or irregularly lobed, 1⁄16″ to 1½″ (2 to 10 mm) wide, and 1⁄32″ to ¾″ (1 to 20 mm) long. It is convex when viewed from the side but depressed near the base. It may be pinkish or brownish-orange to light brown. The upper surface is hairless, opaque, and concentrically wrinkled. When wet it is often slimy or sticky and more or less transparent (hygrophanous). Older specimens are brown with purplish-brown or grayish-brown areas.

The gills are 1⁄32″to ⅛″ (1 to 3 mm) broad and pale yellowish-white or colored like the cap. When a stalk or pseudostalk is present, the gills slightly run down it. They are closely spaced when young, somewhat more widely spaced when mature. There are 16 to 36 gills per ⅜″ (1 cm) at the margin, 14 to 35 gills per ⅜″ (1 cm) at the stalk. The edges of the gills are not gelatinous.

There may be a well-developed stalk, a stalk-like prolongation of the cap (pseudostalk), or no stalk at all. When present, the stalk is firm, attached at the side of the cap (lateral), horizontal to ascending, 1⁄32″ to ⅜″ (1 to 9 mm) long, and 1⁄32″ to 3⁄16″ (1 to 5 mm) wide. It is solid and white when young, becoming hollow and ivory, yellowish, peach, or brown with age. There are usually some coarse white hairs toward the base.

The flesh is thin, firm, fibrous, and white to pale pinkish-tan. Its edibility is unknown and the taste is not distinctive.

The spore print is dingy yellowish-cream.

Sources

24, 26, 29, 30, 77.

Until very recently, this species was known in North America only in the Pacific Northwest. iNaturalist has several dozen citizen observations beginning in 2020 in the eastern United States, including one 2020 observation from Sherburne County in Minnesota. No other source, including GBIF, Encyclopedia of Life, NatureServe, MycoPortal, and Mushroom Observer, has any records east of the Rocky Mountains.

A recently published morphological and molecular DNA analysis of the genus Panellus and related species (Jin, et al., 2001) recommended moving several Panellus species to other genera. Panellus longinquus was moved to the genus Pleurotopsis. In 2012 it was moved to the genus Scytinotus, but the move was not universally adopted. MycoBank uses the name Scytinotus longinquus, Index Fungorum uses the name Panellus longinquus.

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Location: Duluth, MN