2. Materials & Methods
Samples of the aerial parts of Pterospartum tridentatum were collected at different vegetative stages:
dormancy period (end of January) and flowering period (in May). The shrubs were collected in three
locations in Beira Interior, Portugal: Orvalho, Gardunha mountain and Malcata mountain. The
characterization of harvesting areas is shown in Table 1, indicating the altitude and the means annual
precipitation and temperature and also the type of soil where plants were harvested (Table 1).