Usnea subscabrosa Nyl. ex Motyka
Thallus variable: 4-5 cm if erect, 5-10 cm if hanging, but most often in a tuft of tangled twigs of 10-20 cm on the vertical faces of the rocks or on the ground or low vegetation, formed of fairly rigid, starting from a base that is not blackish but sometimes reddish or wine-red, the main branches not narrowed at the base, have rare rings that are not cracked and covered with punctate soralia, small and less than half the width of the branch, numerous and regularly distributed, and sometimes (especially in the youth) of tiny fragile and non-persistent isidiomorphs, the secondary branches are often terminated by fibrils (isidiofibrils) sometimes very abundant in very exposed situations, see Usnea subscabrosa forme saxicole exubérante. The cortex is relatively hard, smooth and shiny and is 8-15% of the diameter, the vitreous medulla. The general coloration is pale greenish-gray in humid weather, pale yellowish-gray in dry weather. Medulla: C-, K-, KC-, P + orange to reddish (several known chemotypes). Hyperoceanic species coming to our prospection area on the ground at the base of rocks or in low vegetation (Heathlands with Calluna and Erica, ..) but also hanging on the rocks of the Caps very exposed and windy at the seaside. Often in company. Usnea flammea with which it is easily confused (and with which it has been confused!). Also pay attention to the young forms of Usnea articulata on the ground, the branches of which are not yet "sausage-like" swelling.