Plants of the Gila Wilderness

Usnea cirrosa is similar to Usnea arizonica, a common gray-green fruticose lichen on Douglas fir trees. However, the fibrils along the branches of U. cirrosa are stiff and all about the same length. They are more lax and varied in length on U. arizonica. These same spiny fibrils are found on the backs of the apothecia on U. cirrosa, while they usually are not on U. arizonica. The medulla of U. arizonica is red in KOH, while there is no reaction with U. cirrosa.
Please click on an image for a larger file.

Usnea cirrosa, photo Russ Kleinman & Karen Blisard, Black Range, Railroad Canyon, April 1, 2018

Usnea cirrosa, macro of branch with equal length fibrils and apothecium with fibrils on back side, photo Russ Kleinman & Karen Blisard, Black Range, Railroad Canyon, April 1, 2018

Usnea cirrosa, photomicrograph of medulla in KOH (negative), photo Russ Kleinman & Karen Blisard, Black Range, Railroad Canyon, April 1, 2018