Spores; Habitat: Rhyolite barrens with sparse bunchgrasses and abundant Selaginella; Location: Above John Day River, just S of junction of Routes 19 and 207; Substrate: Rock, rhyolite; Elevation: 780 meters.
Habit; Habitat: Open rocky ridge with adjoining forest of Pseudotsuga and Castanopsis chrysophylla, with patches of old Arctostaphylos columbiana; Location: Horse Rock Ridge ACEC, foothills of Cascade Range; Substrate: Rock, volcanic; Elevation: 760 meters.
Habit; Habitat: Caliche patch in steppe with Poa secunda, Bromus tectorum, Kochia prostrata, and Elymus elymoides; silty soils, nearly flat; Location: Just north of I-84 NW of Mountain Home; Substrate: Rock, caliche fragments; Elevation: 998 meters; Notes: A. americana det. Knudsen 2011.
Hymenium; Habitat: Open rocky ridge with adjoining forest of Pseudotsuga and Castanopsis chrysophylla, with patches of old Arctostaphylos columbiana; Location: Horse Rock Ridge ACEC, foothills of Cascade Range; Substrate: Rock, volcanic; Elevation: 760 meters.
Spores; Habitat: Open rocky ridge with adjoining forest of Pseudotsuga and Castanopsis chrysophylla, with patches of old Arctostaphylos columbiana; Location: Horse Rock Ridge ACEC, foothills of Cascade Range; Substrate: Rock, volcanic; Elevation: 760 meters.
Habit; Habitat: Open rocky ridge with adjoining forest of Pseudotsuga and Castanopsis chrysophylla, with patches of old Arctostaphylos columbiana; Location: Horse Rock Ridge ACEC, foothills of Cascade Range; Substrate: Rock, volcanic; Elevation: 760 meters.
Soralia; Habitat: Dry subalpine meadows with Pinus albicaulis and Abies lasiocarpa and both limestone and granite outcrops; Location: Pass on trail to Twin Lakes from Storm Lake, Anaconda Range; Substrate: Rock, granite; Elevation: 2664 meters; Notes: Pl. 347: nil. Plate 350: nil.