Platismatia stenophylla

The upper thallus of P. stenophylla is whitish, tan, or pale brown, occasionally somewhat darkening. It has narrow, linear lobes with strongly incurved margins and a smooth upper surface. The lower surface is whitish, tan or brown, minutely reticulate rugose, sometimes veined at ridge crests, darkening but not punctate. It has few black rhizines, present only at places of attachment.^[4]

Platismatia stenophylla reproduces primarily through sexual means. Its apothecia (reproductive structures) are red-brown and shiny, broad, and may be perforate or not. The subhymenium is often underlain with algae.^[4]

Chemical analysis has revealed that P. stenophylla contains caperatic acid and atranorin as lichen products.^[3][4]

Platismatia stenophylla is found in western North America, from Vancouver Island south to central California, usually close to a shore.^[3] It has a largely sympatric range with P. herrei on the West Coast of North America, although P. stenophylla has a slightly smaller distribution.^[4]

Further research with increased sampling and additional genetic loci is needed to fully resolve the relationship between P. stenophylla and P. herrei and to better understand their distribution patterns.^[4]