Names: Amygdalaria panaeola, Powdery Almond Lichen

Identification Characteristics

Description: Thallus dispersed areolate to verrucose; areoles dissolve into coarse granular soredia especially at the base or sides;

Color: Pale brownish gray to yellowish pink.

Cephalodia: Dark pink or olive (depending on the photobiont) brain-shaped galls on or between the areoles.

Chemistry: Soralia C+ red; cortex PD-, K-, KC+ red, C+ red (rarely C-); medulla PD-, K-, C-, KC- (gyrophoric acid often with confluentic acid & related compounds).

Substrate: Rocks in high altitudes in Arctic; humid rock faces such as those near waterfalls when in lower elevations & latitudes.

Range: All but eastern Alaska, west coast of Canada, northeast US & Canada as well as eastern Canada.

Lookalikes: This lichen is almost always sterile & is best distinguished from most other sterile crustose lichens on rocks by its combination of cephalodia & soredia, & by its chemistry.  Coccotrema pocillarium is a sorediate, usually sterile crustose lichen on bark in humid coastal forests of the Pacific Northwest.  It contains stictic acid (PD+ orange, K+ yellow).  Most other species of Amygdalaria are relatively rare & are confined to the humid northwest coast from Washington to southeastern Alaska.

Bibliography: Lichens of North America, by Brodo, Sharnoff, & Sharnoff

Database Entry:  Distance Everheart 12-26-13