The genetic diversity and population structure of two endemic Amazonian quillwort ( L.) species.

Background: Two endemic lycophyte species and have been recently described in the State of Pará in the Amazon forest located in northern Brazil. L. has survived through three mass extinctions.

Arsenic hyperaccumulation in Pityrogramma calomelanos L. (Link): adaptive traits to deal with high metalloid concentrations.

Pityrogramma calomelanos is interestingly the single non-Pteris arsenic (As)-hyperaccumulating fern. It has been pointed as a potential species for phytoremediation and a model plant to study the As toxicity and its mechanisms of action. In order to investigate the morphoanatomical traits associated to As tolerance, P.