Alectoria nigricans (aka “Gray Witch’s Hair”)
Substrate: Normally a soil lichen in tundra heath, but occasionally growing on the low branches of trees or shrubs.
Range. Tundra heath throughout northern & western Canada, western Montana, & northern Washington.
Description: Thallus shrubby, growing erect or tangled on the ground; main branches varying from pale pinkish gray to almost black, but always with black branch tips, surface almost always dull. Large brown apothecia sometimes produced.
Chemistry: Cortex & medulla PD+ yellow, K+ yellow, KC+ red, C+ pink (alectorialic acid). In very dark specimens, these reactions are difficult to see, but they can be discerned with the filter paper method.
Lookalikes: This is the only Alectoria that is grayish instead of yellowish (lacking usnic acid in the cortex). The darkest thalli can be mistaken for Bryoria nitidula, but that lichen almost always has some shiny brown parts & its medulla is PD+ red. Even the darkest specimens of A. ochroleuca typically have some yellow at the base, but the two species can be very similar otherwise; chemistry will distinguish them.
Bibliography: Lichens of North America, by Brodo, Sharnoff, & Sharon
Database Entry: Distance Everheart 12-26-13