To cite package ‘geneplast’ in publications use:

  Dalmolin RJS, Castro MAA. Geneplast: evolutionary rooting and
  plasticity inference. R package, 2015.

A BibTeX entry for LaTeX users is

  @Manual{,
    author = {{Dalmolin} and Rodrigo JS and {Castro} and Mauro AA},
    title = {Geneplast: evolutionary rooting and plasticity inference},
    year = {2015},
    note = {R package},
  }