Plagiochasma rupestre (J.R Forst. & G. Forst.) Steph.  

The thallus is oblong, elongated, furcate with purplish borders.  It is waxy grey / blue green in colour. It is glaucous.  Small simple pores, which cannot be seen with a hand lens, are found on its surface.  Large purple scales, with a metallic sheen, are found on the ventral surface.  They have a lanceolate appendage with a constriction near the tip.  They appear as one row on each side of the midrib.  The terminal appendages of the scales project beyond the margins at the apex in young lobes. Here the appendage is usually discoloured. 

Female gametophytes can be seen on the central line of the thallus.