FRUIT BODY 5–20 mm high overall. HEAD 2–5 mm wide, convex to rounded. Bright to pale orange-yellow to orange; rarely reddish orange in age. STIPE 4–20 mm long, 1–2 mm thick, whitish to grayish at first, often finely scurfy with dark scales, darkening from the base up, gray to blackish in age. FLESH thin, watery, somewhat translucent. MICROSCOPY: Spores (80) 125–250 x 1 μm, highly variable in length, thread-like, multiseptate. Asci 175–325 x 5–6 μm, narrowly clavate. Paraphyses straight, simple or branched, thread-like in lower part, enlarged at tips.
ECOLOGY: Saprobic on saturated or submerged twigs, branches, and small logs in creeks, seeps, or other water sources. Fruitings occur scattered or in gregarious troops. Fruit bodies can be found completely underwater or with the heads above water and the substrate submerged. The only California collection came from a creek surrounded by alder (Alnus spp.), in montane forest at 1750 m.
SIMILAR SPECIES: A similar species (also rare) that occurs in the same habitat is Vibrissea filisporia. It can be distinguished by its paler yellow color, and short or nearly absent stipe. It occurs on submerged twigs and branches of hardwoods. Mitrula elegans is taller, has an oblong to cylindrical, bright orange head, and a thin, proportionally longer, translucent-white stipe. It grows on grass, sedge, and leaf debris in slow-moving water.