Apothecia sessile to substipitae, shallowly cupulate to dish-shaped, 3-8 mm broad at maturity; margin level to incurved, often wavy, lined with short bristly brown, sometimes hyaline-tipped hairs (use hand lens); in dry weather the cup exterior frequently folded over the fertile surface; hymenium glabrous, smooth to slightly wrinkled, cream, buff, yellow to yellowish-orange; external surface densely covered with short brown hairs often matted in age; fruiting body hygroscopic, reviving after drying.
Spores 7.0-9.0 x 4.0-5.0 µm, ellipsoid, smooth, thin-walled, inamyloid; asci uniseriate; spore deposit not seen.
Gregarious to clustered on bark of downed montane conifers; fruiting during the spring; present in dried state throughout the year; common.
Small and tough, of no culinary value.
Lachnellula arida is recognized by cups that are brown and minutely hairy with a cream to yellowish hymenium. As suggested by the species name, it often fruits in dry sites where it would appear to be vulnerable to dessication. The ascocarps, however are resilient, shriveling in dry conditions, reviving when moisture returns, a process that can be repeated numerous times. Lachnellula arida is common throughout the montane regions of California and western United States. It is best seen in the spring following snowmelt, or after moistening summer thunderstorms.