Alectoria (aka “Witch’s Hair”)
Substrate: on bark, wood, soil, rock, or arctic-alpine sod
Habitat: On bark & wood in conifer forests & tundra, on ground, rarely on rock, in well-lit situations.
Description: Erect or tufted, pendulous, or prostrate; light greenish yellow or pale green (rarely gray to black– although one sp. is particularly blackish) with slender, hair-like, generally teret branches basically round in cross section or sometimes partially flattened, angular, or pitted; supporting tissue in the cortex; medulla dense or cottony; raised, whitish, elongate pseudocyphellae (isidioid spinules arising from the pseudocyphellae in one sp.) present on the branches of all species; isidia & soredia absent; photobiont green (Trebouxia?). Apothecia lateral & Parmelia-like but infrequent, scattered along the branches; spores large, brownish, 1-celled, 2-4 per ascus; disk tan, dark brown, or blackish; pycnidia rare.
Chemistry: Cortex PD-, K-, KC+ yellow, C- (usnic acid present in all but A. nigricans); medulla often with orcinol depsides, reacting K+ yellow or K-, P+ yellow or P-; KC+ red or KC-; KC+ gold; C+ red.
Lookalikes: Can resemble pendulous Usnea in color & habit, but Alectoria has not axis. Greenish-yellow species of Alectoria can be mistaken for Ramalina or Evernia. Evernia is usually soft & pliable & doesn’t have raised white pseudocyphellae. Ramalina usually has flattened branches; the species with round, slender branches (like R. thrausta) have tips that curl up & develop a few granules, & the pseudocyphellae– if present– are more like dots.
Bibliography: Macrolichens of the Pacific Northwest, Bruce McCune & Linda Geiser, Lichens of North America, by Brodo, Sharnoff, & Sharnoff
Database Entry: Distance Everheart 12-26-13