Samples containing leaves of three different plants identified as P. pseudocaryophyllus were collected bimonthly from January 2009 through November 2009, from the same locality in a restinga in the Ilha Comprida municipality, state of Sao Paulo, Atlantic Rain Forest, southeastern Brazil.

Seven compounds were identified and characterized, revealing a predominance of phenylpropanoids (15.4-70.9%) and variable amounts of monoterpenes (0.5-5.3%). The composition of the oil changed month by month. The best yield of oil was obtained in November, and the major component chavibetol was present in all samples (50.2-70.9%). The chavibetol content showed significant seasonal variation, with the maximum percentages of 69.1% and 70.9% measured in January and November, respectively.

Two samples were collected in Sao Goncalo do Abaete, one in July 2000 and the other in November 2005, in periods of post-anthesis and preanthesis, respectively.

Thirty compounds were detected in the samples collected in Sao Goncalo do Abaete. Among the identified compounds, 53.8% are sesquiterpenes and 42.3% are monoterpenes. The majority components in the two samples were neral and geranial. The sample in anthesis presented a lower percentage of neral (21.4%) and geranial (36.5%) than the sample in pre-anthesis, whose percentages of neral and geranial were 33.6% and 47.2%, respectively.